Pseudoneoplastic lesions of the testis and paratesticular structures Pseudotumors or tumor-like proliferations -LRB- non-neoplastic masses -RRB- and benign mimickers -LRB- non-neoplastic cellular proliferations -RRB- are rare in the testis and paratesticular structures . Clinically , these lesions -LRB- cysts , ectopic tissues , and vascular , inflammatory , or hyperplastic lesions -RRB- are of great interest for the reason that , because of the topography , they may be relevant as differential diagnoses . The purpose of this paper is to present an overview of the pseudoneoplasic entities arising in the testis and paratesticular structures ; emphasis is placed on how the practicing pathologist may distinguish benign mimickers and pseudotumors from true neoplasia . These lesions can be classified as macroscopic or microscopic mimickers of neoplasia . Introduction There are many lesions that can simulate a neoplasm in the testis or paratesticular structures . Their incidence among tumors arising within the scrotal sac varies according to different series from 6 to 30 % -LSB- 16 , 32 -RSB- . These pseudoneoplastic lesions can be divided into those that only macroscopically imitate neoplasia -LRB- Table 1 -RRB- and those that microscopically imitate neoplasia , regardless of whether they form a macroscopic mass -LRB- Table 2 -RRB- . The latter group causes more problems to the practicing pathologist in terms of the correct classification of a giving lesion . Hereby , we summarize main tumor-like lesions and benign mimickers that may be seen in the testis and paratesticular coverages , with emphasis on morphologic criteria for the differential diagnosis from true neoplasia . Table 1Macroscopic mimickers -LRB- pseudotumors -RRB- of testicular and paratesticular neoplasiaVascular lesions Intratesticular hemorrhage Segmental testicular infarction Organizad testicular hematocele Cholesterol granuloma of the tunica vaginalisInflammatory lesions Nonspecific infectious inflammatory lesions Specific infectious inflammatory lesions Non-infectious inflammatory lesions Idiopathic inflammatory lesions Idiopathic granulomatous orchitis Testicular malakoplakia Testicular sarcoidosis Meconium periorchitis Sperm granulomaCysts Testicular cysts Albuginea cysts Parenchymal cysts -LRB- Epidermoid cysts -RRB- Rete-testis cysts - Cystic displasia of the rete testis Epididymal cysts and Spermatoceles Spermatic cord cystsEctopic tissues Adrenal cortical rests Spleno-gonadal fusionTesticular appendagesMiscellaneous other lesionsFibrous pseudotumors ; -LRB- Fibromatous periorchitis-Nodular periorchitis -RRB- Amyloidosis Polyorchididm Sclerosing lipogranulomaTable 2Microscopic mimickers of testicular and paratesticular neoplasiaTesticular Inflammatory-reactive lesions Lymphocitic orchitis -LRB- Testicular pseudolymphoma -RRB- Rosai-Dorfman disease Sertoli cell hyperplasia Pick adenoma Hamartomatous proliferation testicular feminization syndrome Interstitial cell hyperplasia Leydig cell hyperplasia Testicular `` tumor '' of the adrenogenital syndrome Hyperplasia of the rete testisEpididymis Adenomatoid hyperplasiaTunicas albuginea-vaginalis Mesothelial hyperplasiaSpermatic cord Vasitis nodosa Inflammatory pseudotumor -LRB- Funiculitis proliferans -RRB- Miscellaneous other lesions Macroscopic mimickers -LRB- pseudotumors -RRB- of testicular and paratesticular neoplasia This group of lesions refers to those that macroscopically imitate a neoplasia . Frequently , these lesions affect both compartments and are therefore difficult to establish if one or both are affected . For this reason , we classify the tumor-like lesions according to their etiology . Vascular lesions The majority of the vascular disorders of the male gonad are not confused with a tumor because , in addition to causing acute symptoms , they usually affect the entire gonad . However , in the rare situation in which the vascular lesion is segmental , it can simulate neoplasia , as follows : Intratesticular hemorrhage , which occurs spontaneously -LSB- 24 -RSB- or in the context of anticoagulation treatment -LSB- 15 -RSB- , may simulate a tumor at ultrasound examination.Segmental testicular infarction , a lesion clinically characterized by slight local pain unrelated to any acute episode -LSB- 20 -RSB- , may be related to isolated or systemic vasculitis -LSB- 43 , 103 -RSB- with morphology of polyarteritis nodosa -LSB- 21 -RSB- , giant cell vasculitis -LSB- 94 -RSB- , or Wegener granulomatosis -LSB- 45 -RSB- . Up to year 2000 , 81 cases of systemic vasculitis with testicular tumor-like lesion have been recorded -LSB- 45 -RSB- . Other cases are seen in the context of a hematological disease -LRB- sickle cell anemia -RRB- -LSB- 53 -RSB- or associated with nonspecific perivascular fibrosis . Any of the phases of an infarction can be observed from acute -LRB- with hemorrhage -RRB- to healing stage -LRB- Fig. 1 -RRB- . Currently , the clinical diagnosis can be suspected with Doppler sonography -LSB- 81 -RSB- , avoiding orchiectomy.Organized testicular hematocele and other hemorrhages in the tunica vaginalis are rarely confused with a neoplasia -LSB- 89 -RSB- , but this can happen occasionally in long-standing cases because of fibrous thickening with cholesterol granuloma formation in the tunica vaginalis -LRB- Fig. 2 -RRB- -LSB- 61 -RSB- Exceptionally , a true testicular neoplasia presents clinically with a hematocele -LSB- 86 -RSB- . Fig. 1Segmental testicular infarction . a Acute hemorrhagic with reinforcement of the peripheral area -LRB- arrows -RRB- . b Healing fibrosisFig . 2Cholesterol granuloma in the tunica vaginalis -LRB- H&E -RRB- Inflammatory lesions Similar to what was stated for vascular tumor-like lesions , inflammation that simulates a neoplasia usually has atypical clinical features ; these entities can be grouped as follows : Nonspecific infectious inflammatory lesions with a tumor-like presentation are frequently chronic processes causing progressive fibrosis , which may clinically -LSB- 38 -RSB- or sonographicaly -LSB- 23 -RSB- simulate neoplasia . Rarely a testicular , epididymal , or vas deferens abscess can look like a neoplasia -LSB- 84 -RSB- . Very occasionally , testicular neoplasia can clinically imitate an acute inflammatory process -LSB- 44 -RSB- . Specific infectious inflammatory lesions . The entities of this group that most often have been confused with neoplasias are granulomatous inflammation in tuberculosis -LSB- 87 -RSB- , brucellosis -LSB- 49 -RSB- , syphillis -LSB- 5 -RSB- , fungal infections -LSB- 42 -RSB- , and parasite diseases -LSB- 9 -RSB- . These lesions are usually not problematic for the pathologist.Noninfectious inflammatory lesions . This group of tumor-like lesions include different entities among which can be highlighted : Idiopathic granulomatous orchitis , probably of autoimmune aetiology , of which around 230 cases have been published -LSB- 4 -RSB- , is characterized by tubular granulomas -LRB- tubular orchitis ; Fig. 3 -RRB- or interstitial granulomas -LRB- interstitial orchitis -RRB- . The presence of intratubular giant cells differentiate this entity from infectious granulomatous orchitis -LSB- 70 -RSB- . Diffuse testicular hypoechoic involvement with only peripheral low-resistance flow on color Doppler sonography is a typical but not pathognomonic pattern -LSB- 72 -RSB- . Malakoplakia . This lesion is secondary to a mononuclear decrease in cyclin -- guanine monophosphate that impairs the killing of bacteria . Fusion of the phagolysosomes with bacterial rests produces the characteristic Michaelis -- Gutman bodies in the cytoplasm of the macrophages -LRB- von Hansemann cells -RRB- -LSB- 1 -RSB- -LRB- Fig. 4 -RRB- . Giant cells are occasional or absent . Testicular involvement represents only 12 % of genital malakoplakia with around 388 cases in the literature -LSB- 19 , 56 -RSB- ; exceptionally , it may affect the epididymis only -LSB- 31 -RSB- . It has been related to idiopathic granulomatous orchitis -LSB- 56 , 57 -RSB- and chronic xantogranulomatous inflammation of testis -LSB- 85 , 109 , 110 -RSB- ; this last also reported in the spermatic cord -LSB- 64 , 100 -RSB- . Sarcoidosis . Testicular involvement in a systemic sarcoidosis -LSB- 39 -RSB- is exceedingly rare , and its presentation as the primary form is even rarer ; in these cases , the epididymis is affected more with the testicle being involved by contiguity -LSB- 83 -RSB- . Meconium periorchitis . This is an infrequent lesion -LRB- around 30 cases being reported -RRB- that typically presents in the first months of life ; most times there is a clinical history with obstetric problem that has caused the passing of meconium toward the testicular surrounding structures -LSB- 29 -RSB- . The macroscopic appearance is a myxoid material with calcified pearls resulting from the calcification of the remains of squamous cells or lanugo hairs -LSB- 107 -RSB- -LRB- Fig. 5 -RRB- . Suspicion of neoplasia , although very uncommon in this period of life , may be caused by a scrotal mass or sonographically detectable calcifications -LSB- 6 -RSB- . Clinically , the peritesticular and spermatic cord enlargement can simulate a paratesticular rhabdomyosarcoma.Sperm granuloma . As its name indicates , this granulomatous lesion with few giant cells is the consequence of extravasation of spermatozoa generally postvasectomy -LRB- 40 % of vasectomized men and 2.5 % of general population -RRB- -LSB- 108 -RSB- . When it produces a tumor-like lesion , it is usually located in the deferent duct or the epididymis -LSB- 22 -RSB- with firm nodules of 0.7 to 4 cm with occasional cysts formation.Fig . 3Idiopathic granulomatous orchitis characterized by tubular granulomas -LRB- tubular orchitis -RRB- Fig. 4Malakoplakia . a Macroscopic appearance with a homogeneous aspect . b The characteristic Michaelis -- Gutman bodies in the cytoplasm of the macrophages -LRB- von Hansemann cells -RRB- -LRB- PAS -RRB- Fig. 5Meconium periorchitis . a calcified pearls resulting from the calcification of the remains of squamous cells or lanugo hairs . b Keratin rest in one of the calcifications -LRB- H&E -RRB- Cysts The majority of the cysts with a tumor-like appearance are paratesticular structures , but the testicle may occasionally have some cystic lesions that can be confused with a neoplasia . Testicular cysts occur in approximately 8 -- 10 % of patients with a lump in the testis , including those of the tunica albuginea or the parenchyma -LSB- 33 -RSB- . Tunica albuginea cysts do not usually cause any diagnostic problem , unless if they are complex cysts -LSB- 74 -RSB- . Parenchyma testicular cysts can be more difficult to distinguish from a neoplasia and if there is the slightest suspicion of an intracystic content , one must suspect a malignant neoplasia -LSB- 107 -RSB- . Special consideration deserves the testicular Epidermoid cyst , which must only be lined with squamous epithelium -LRB- Fig. 6 -RRB- . It is recommended that the specimen is examined `` in toto '' to avoid underdiagnosis of any area of teratoma -LRB- especially among postpuberal patients -RRB- or intratubular germ cell neoplasia , as sonographically it is not possible to distinguish between these lesions -LSB- 54 , 106 -RSB- . Epidermoid cysts represent 1 % of the masses of the testes . Recent genetic studies have shown that there is no chromosome 12p abnormality -LSB- 14 -RSB- , thus supporting its distinction from teratoma.Tubular ectasia of the rete testis secondary to obstruction and generally located in the mediastinum area of the testes -LRB- Fig. 7 -RRB- -LSB- 69 -RSB- , is usually bilateral and very different from cystic dysplasia of the rete testis , a congenital lesion with complete testicular parenchyma substitution -LSB- 68 -RSB- . Epididymal cysts and spermatoceles are relatively frequent and the majority are in relation to the inflammatory processes . The differential diagnosis with other entities are related to its size , and similar to the other cystic formations a true neoplasia must be considered in case of observing any content in its interior -LSB- 108 -RSB- . Spermatic cord cysts . The majority of these cysts do not cause any diagnostic doubts , only the occasional Epidermoid cysts -LSB- 46 , 105 -RSB- can simulate a neoplasia . These cysts can be unilocular or multilocular depending on their origin -LSB- 65 -RSB- , and the multilocular must be distinguished from the exceptional cystadenomas of probably Müllerian origin -LSB- 55 -RSB- . Fig. 6Epidermoid cyst , which must only be lined with squamous cell epithelium -LRB- H&E -RRB- Fig. 7a Tubular ectasia of the rete testis located in the mediastinum area of the testes -LRB- arrows -RRB- . b Microscopic aspect -LRB- H&E -RRB- Ectopic tissues Ectopic adrenocortical tissue is relatively frequent in the tunica albuginea , rete testis , epididymis , and spermatic cord and occasionally reaches the size to be symptomatic . Its incidence ranges from 2.5 to 15 % -LSB- 17 , 102 -RSB- . It is made up of adrenal cortical nodes surrounded by a connective tissue band and of about 5 mm in diameter on average -LRB- Fig. 8 -RRB- ; for which reason , they are not clinically palpable . Only in cases of congenital adrenal hyperplasia or Cushing syndrome , ectopic adrenocortical tissue can be prominent and appear as a tumor-like lesion -LSB- 90 -RSB- . Splenic -- gonadal fusion , as its name indicates , is the fusion of spleen and gonad . It is more frequent on the left side , with about 148 published cases -LSB- 41 -RSB- . Morphologically , the ectopic splenic tissue can be in close relation to the head of the epididymis or the upper pole of the testis -LRB- Fig. 9 -RRB- or being separated from it ; likewise , there may or may not be a structural continuity between the normal spleen and the ectopic tissue -LSB- 30 -RSB- . The same alteration has been described in women , but it is much less frequent that in men , probably because it is much easier to find it clinically in men . In about 30 % of the cases , it is associated with complex malformations such as micrognathia , peromelia , or phocomelia -LRB- absence of upper portion of a limb -RRB- -LSB- 30 , 60 , 95 -RSB- . In three of the reported cases , the fusion was associated with a germ cell tumor of the testis -LSB- 41 -RSB- . An exceptional hepato-gonadal fusion is reported -LSB- 26 -RSB- . Fig. 8 Ectopic adrenocortical tissue . Adrenal cortical nodes surrounded by a connective tissue band in continuity with epididymis . -LRB- H&E -RRB- Fig. 9 Splenic -- gonadal fusion . The ectopic splenic tissue in close relation with the upper pole of the testis -LRB- H&E -RRB- Testicular appendages There are five testicular appendages , but for the surgical pathologist , only three can be of interest -LRB- appendix testis or hydatid of Morgagni , appendix epididymis , paradidymis or organ of Giraldes ; Fig. 10 -RRB- . These structures are not usually the origin of a tumor-like lesion , but in rare cases of large-sized cysts , it may presents as a paratesticular mass -LSB- 93 -RSB- . A case of ectopic epididymal tissue in an appendix testis -LSB- 101 -RSB- has recently been reported . Fig. 10Normal testicular appendages Miscellaneous other lesions Fibrous pseudotumors . This name refers to a fibrosis phenomenon with paucicellular hyalinized collagen -LRB- Fig. 11 -RRB- presenting as nodular -LRB- single or multiple -RRB- or diffuse lesion of the testicular tunics -LSB- 96 , 71 -RSB- . Sometimes , a node can be free -LRB- scrotal mouse -RRB- -LSB- 108 -RSB- . This broadly considered spectrum of lesions has received diverse names : chronic periorchitis , fibromatous periorchitis , nodular periorchitis , fibrous proliferation of the tunica , nonspecific paratesticular fibrosis , granulomatous periorchitis , nodular fibrous pseudotumor , fibrous pseudotumor , inflammatory pseudotumor , fibroma , reactive periorchitis -LSB- 108 -RSB- , indicating its controversial pathogenesis . Some cases have been reported preceded by trauma or infection , and on occasion , an inflammatory component can be observed and granulation tissue suggesting the possibility that there might be the healing of an inflammatory pseudotumor , -LRB- which will be described later on -RRB- -LSB- 10 -RSB- . Although radiologically , it is not difficult to recognize , upon occasion , an intraoperative frozen section becomes necessary . Amyloidosis . It is usually bilateral and present in a patient with a prior history of amyloidosis -LSB- 34 -RSB- ; more rarely , it is a primary form that by being a cryptorquidic patient simulates a testicular tumor -LSB- 13 -RSB- . Polyorchidism or supernumerary testes is a rare condition , which is easy to recognize . However , the sonography can occasionally be different from that of the normal testis , and the condition may then be tumor suspicious -LSB- 79 -RSB- . Fig. 11 Fibrous pseudotumor . a Well outlined fibrous-like nodule . b Paucicellular hyalinized collagen with calcification Microscopic mimickers of testicular and paratesticular neoplasia Lesions or cellular changes that microscopically imitate a neoplasia are included under this category , whether or not they make a clinical mass . These changes are closely related to the structure of the organ in which they arises , as follows . Testicular Inflammatory-reactive lesions Some lesion , already described above such as xantogranulomatous orchitis , idiopathic granulomatous orchitis and malakoplakia could be considered under this category ; their microscopic confusion with a neoplasia -LRB- seminoma for example -RRB- is not currently a usual event ; therefore , we preferred to include them in the macroscopic mimickers -LRB- pseudotumors -RRB- . The situation is different with lymphocitic orchitis or testicular pseudolymphoma -LSB- 2 , 3 -RSB- , which is characterized by a lymphocytic and plasmocellular reaction that may be confused with a lymphoma , but immunohistochemistry will show that the cellular infiltrate is polyclonal -LRB- Fig. 12 -RRB- . Among these idiopathic lesions , we can include Rosai -- Dorfman disease ; histological examination of the testicular mass reveals an inflammatory lesion comprising lymphocytes , plasma cells , and sheets of pale staining histiocytes , some containing lymphocytes within their ample cytoplasm , suggestive of emperipolesis . The histiocytes stained positive for CD68 , S100 by immunohistochemistry and negative for CD1a , while ultrastructural examination confirmed emperipolesis -LSB- 25 -RSB- . Fig. 12Lymphocitic orchitis . Lymphocitic cellular infiltration of polyclonal type . a CD45RA -LRB- lymphocytes B -RRB- . b UCHL-1 -LRB- lymphocytes T -RRB- Sertoli cell hyperplasia In a series of situations , nonencapsulated nodules of Sertoli cells can be found , especially known in cryptorchid testes as Pick 's adenomas -LRB- Fig. 13a -RRB- -LSB- 77 -RSB- . Because of their appearance , these should be distinguished from the actual Sertoli cell tumors that generally are larger and sometimes there are areas that mimic Call -- Exner bodies -LRB- Fig. 13b -RRB- A differential diagnosis with a yolk-sac tumor is not usually in the scope , but the immunohistochemistry study with AFP , calretinin , α-inhibin , and CD 99 can help -LSB- 40 -RSB- . Fig. 13Sertoli cell hyperplasia . a Nonencapsulated nodules of Sertoli cells -LRB- Pick 's adenoma -RRB- . b Sometimes there are areas that mimic Call -- Exner bodiesA special consideration merit the androgen insensitivity syndrome or testicular feminization -LRB- male pseudohermaphrodism , caused by a failure of androgen receptor binding -RRB- that in 63 % of cases can have tubular hamartomas -LRB- tubules lined by immature Sertoli cells -RRB- -LSB- 82 -RSB- that must be differentiated from the Sertoli cell adenomas and sex cord tumor with annular tubules -LSB- 76 -RSB- . Interstitial cell hyperplasia In testicles with marked tubular atrophy , such as in the Klinefelter 's syndrome , it is possible to see Leydig cell nodules that must be distinguished from Leydig cell tumors . An interstitial growth without expansive pattern favors hyperplasia -LRB- Fig. 14 -RRB- -LSB- 62 -RSB- . Fig. 14Leydig cell hyperplasiaNodules of eosinophilic cells appearing to be Leydig cells are found in the patients with adrenogenital syndrome -LSB- 18 , 48 -RSB- and Nelson 's syndrome -LRB- adrenocorticotropic hormone-secreting pituitary adenoma after bilateral adrenalectomy -RRB- , some of this last syndrome with excessive testosterone production -LSB- 91 -RSB- ; proof that these interstitials cells are not only morphologically similar to Leydig cells but also have the functional property of these cells . These nodules are usually bilateral and of a large size with cellular pleomorphism and pigmentation . The clinical history and a complete endocrinological profile avoid an unnecessary orchiectomy -LSB- 78 -RSB- because only one case of aggressive behavior is published -LSB- 18 -RSB- . Hyperplasia of the rete testis The normal rete testis epithelium is flat , but in some hyperestrogenic situations -LRB- treatment or hepatic dysfunction -RRB- , the epithelium may become columnar and rarely a micropapillary growth of bland cells can be observed . The diagnosis of rete testis hyperplasia is subjective , and adenomatous lesions are rarely seen -LSB- 35 , 63 -RSB- . In some cases , there are intracytoplasmic hyaline eosinophilic globules resembling a yolk sac tumor , but the negative stains of α-fetoprotein or placental alkaline phosphatase help to rule this differential diagnosis -LSB- 99 -RSB- . Pseudohyperplasia of the rete testis and epithelial reaction in case of germ cell invasion and cryptorchidism must be differentiated from real hyperplasia of the rete testis -LSB- 62 -RSB- . Epididymis Benign microscopic mimickers of cancer in the epididymis are very rare . Cysts may occur but do not resemble tumors microscopically . However , some cases of adenomatoid hyperplasia of the rete testis can involve the epididymis , and occasionally , they may become macroscopically apparent -LSB- 93 -RSB- . Tunica albuginea and vaginalis Non-neoplastic mesothelial lesions involving the paratesticular region include mesothelial cysts and reactive mesothelial hyperplasia -LSB- 73 -RSB- . Mesothelial hyperplasia is the most important benign mimicker of the testicular tunics . It is present as a reactive lesion in hydrocele or hernia but may also be found microscopically in older men -LSB- 80 -RSB- . The mesothelial proliferation has an epithelial appearance , and rarely , a spindle cell proliferation can be present . In the differential diagnosis with mesothelioma , the bland nucleus , no true invasion , and associated inflammatory elements can be useful -LRB- Fig. 15 -RRB- -LSB- 11 , 98 -RSB- . Recently , a case was published with `` atypical '' mesothelial hyperplasia on one side and `` well differentiated '' mesothelioma on the contalateral -LSB- 97 -RSB- . This case is an example of the subjective interpretation of some mesothelial proliferative lesions because some malignant mesotheliomas lack cellular atypia . In these cases , an extensive confluence or prominent infiltration favors a malignant diagnosis . Unfortunately , the immunohistochemical expression of benign and malignant mesothelial proliferations are similar -LRB- low - and high-molecular-weight cytokeratins and vimentin -RRB- -LSB- 11 , 28 -RSB- , and only the metastatic neoplasias can be differentiated by the CEA , Ber-EP4 , and B72 .3 expression -LSB- 27 -RSB- . Only deoxyribonucleic acid ploidy can distinguish some borderline lesions -LSB- 28 -RSB- . Fig. 15Mesothelial hyperplasia . The bland nucleus , no true invasion and associated inflammatory elements , can be useful to distinguish from malignant mesothelioma Spermatic cord The vas deferens and the soft tissues of spermatic cord can have benign mimickers . Vasitis nodosa is a ductular proliferation , generally after vasectomy -LSB- 36 -RSB- , although it can be seen following other trauma on that area , -LSB- 75 -RSB- . It has a microglandular morphology -LRB- Fig. 16 -RRB- with mild nuclear atipia and perineural growth -LSB- 7 -RSB- or benign vascular invasion -LSB- 8 -RSB- that may be mistaken for malignancy -LSB- 104 -RSB- . The frequent hyperplasia of nerve fibers in the adventitia can explain the painful symptoms in some patients -LSB- 36 -RSB- . The coincidence with microscopic sperm granulomas and inflammatory reaction can help in the correct diagnosis . An analogous epididymal lesion also occur -LSB- 88 -RSB- . Proliferative funiculitis is the inflammation of the spermatic cord usually the result of an extension of vasitis . The soft tissues of the spermatic cord are also the most common site of an inflammatory pseudotumor in the male genital tract -LSB- 37 , 50 , 58 -RSB- . The lesion is ill defined , myxoid with white-gray color , and a moderate cellular proliferation with loose collagen fibers and irregular infiltration of inflammatory cells . An exceptional case has been reported that was largely infiltrated by mast cells -LSB- 92 -RSB- . In some cases , a prominent spindle cell proliferation mimics a sarcoma -LRB- pseudosarcomatous myofibroblastic proliferation -RRB- , but low mitotic index , a capillary pattern , inflammatory cells , and absence of atypical mitoses speak against a diagnosis of sarcoma . Unfortunately , immunohistochemistry is only partly helpful because the cells express actin and vimentin , less strongly desmin and exceptionally cytokeratin . Two cases of this lesion in epididymis -LSB- 12 , 51 -RSB- and one in the rete testis -LSB- 47 -RSB- have been reported.Fig . 16Vasitis nodosa . Ductular proliferation with a microglandular morphology Embryonic remnants Although ectopic tissue usually is more problematic for constituting a mass , some of them can cause microscopic diagnostic doubts for which reason they can be included in this group of benign mimics . The presence of seminiferous tubules within the tunica albuginea -LSB- 67 -RSB- , Leydig cells in rete testis , albuginea , spermatic cord , or within sclerotic tubules -LSB- 59 , 66 -RSB- , prostate gland in the epididymis -LSB- 52 -RSB- , and special circumstances with muscular rete testis hypertrophy -LSB- 27 -RSB- can mimic a neoplasia . The lesions described constitute a large heterogeneous group , without etiological or pathogenic relations among them or with true neoplasias . However , in spite of that , the patient with one or more of these tumor-like and/or benign mimickers can have a concomitant or ulterior true neoplasm .

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O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

testis
paratesticular structures
pseudotumor
benign mimics


Duhamel procedure : a comparative retrospective study between an open and a laparoscopic technique Background Few studies are available comparing open with laparoscopic treatment of Hirschsprung 's disease . This study compares a laparoscopic series of 30 patients with a historical open series of 25 patients . The treatment of Hirschprung 's disease has become less invasive over the years . For a long time the surgical treatment was performed in three tempi : the creation of a proximal diverting ostomy , resection of the aganglionic bowel segment , and restoration of bowel continuity . Since the 1990s the operation is usually performed in one session , without ostomy -LSB- 1 -- 3 -RSB- . In several centers the operation is now undertaken shortly after birth , eliminating the need for bowel washouts in the period between diagnosis and definitive surgical treatment . More recently minimal access techniques have been introduced for taking biopsies to determine the proximal extension of the disease and for dissection of the aganglionic part of the bowel to be removed -LSB- 4 -- 6 -RSB- . Transanal resection of the aganglionic colon has also been performed without taking biopsies at the beginning of the operation in cases with presumed classic extension of the disease -LSB- 7 -RSB- . The treatment for Hirschsprung 's disease in our institution has been the Duhamel technique for a long time . With the introduction of minimal access techniques in the early 1990s , we developed a laparoscopic variant of the open technique and published preliminary results in 1995 -LSB- 4 -RSB- . There is little doubt that the laparoscopic variant of the open Duhamel leads to less pain , a quicker recovery , and better cosmesis , but the question arises whether the operation is as safe as the open one and whether the functional results are comparable . In this study we compare a series of laparoscopic Duhamel procedures with a historical series of open Duhamel procedures . Materials and methods The charts of all patients who underwent a Duhamel procedure in the period from June 1987 through July 2003 were retrospectively analyzed . From June 1987 through March 1994 the Duhamel procedure was performed in an open way -LRB- OD -RRB- , and from March 1994 through July 2003 it was performed laparoscopically -LRB- LD -RRB- . To obtain a relatively homogeneous group of patients , patients were excluded from the study for the following reasons : preoperative colostomy , extended aganglionosis , trisomy 21 , Waardenburg syndrome , or other associated malformations . Preoperative bowel preparation consisted of antegrade washout until the effluent became clear -LSB- 8 -RSB- . The laparoscopic technique was described earlier -LSB- 4 -RSB- . In short , the extension of the aganglionosis was diagnosed by frozen section examination of seromuscular biopsies taken during surgery . Originally the dissection of the rectum was performed circumferentially up to the pelvic floor , allowing the rectal stump to be closed transanally . The latter was difficult and required considerable traction on the stapled side-to-side anastomosis in order to reach the upper part of the stump -LSB- 4 -RSB- . The technique was therefore modified . The anterior dissection was limited to just below the peritoneal reflexion , while posterior dissection was done up to the pelvic floor . Dissection of the bowel in the proximal direction was close to the bowel wall up to a good location for a biopsy . Either the rectum was amputated at the level of the peritoneal reflexion after placing a proximal ligature around the rectum to prevent leakage or the mobilized colon was everted through the anus . The everted rectum was then transected under traction close to the anus , while the bowel was further exteriorized up to the good biopsy location . The everted bowel was then amputated and closed . The everted bowel was reintroduced into the abdomen as was the remaining rectum . About 0.5 cm above the dentate line a transverse incision was made in the posterior rectal wall and the retrorectal space was entered to meet the space dissected from above . The proximal end of the bowel was grasped , pulled through , and anastomosed circumferentially with the created opening in the posterior rectum . A side-to-side anastomosis was then made between the anterior aganglionic rectum and the posterior pulled-through ganglionic bowel using an EndoGIA -LRB- blue cartridge 3.5 cm long ; Tyco Heathcare -RRB- under laparoscopic control . Usually two cartridges needed to be fired . Finally , the upper rectum was closed laparoscopically with a running 2 × 0 Vicryl suture . Outcome measures included postoperative complications , hospital stay , and long-term outcome such as constipation , enterocolitis , fecal incontinence , enuresis , stenosis , and adhesive obstruction . The data were statistically analyzed by using SPSS v9 .0 -LRB- SPSS Inc. , Chicago , IL -RRB- . A p value of less than 0.05 was considered significant . For comparing weight and age between the two groups the t test was used , whereas for hospital stay and start of oral feeding the Mann-Whitney U test was used . Fisher 's exact test was used for comparing the postoperative complications and additional surgical procedures . Data are given as mean -LRB- range -RRB- unless stated otherwise . Results In total 117 patients were operated on during the study period . Sixty-two patients underwent an open Duhamel in the period from June 1987 through March 1994 , and 55 had a laparoscopic Duhamel in the period from March 1994 through July 2003 . After applying the exclusion criteria 25 patients -LRB- 21 males and 4 females -RRB- who underwent an open Duhamel remained and 30 patients -LRB- 23 males and 7 females -RRB- who had a laparoscopic Duhamel remained . Patient characteristics are shown in Table 1 . There were no statistically significant differences between the groups with respect to gender or age at the time of operation . Table 1 . Patient characteristicsOpen DuhamelLaparoscopic DuhamelGender -LRB- m , f -RRB- 21 , 423 , 7Age at diagnosis -LRB- months -RRB- 4.2 -LRB- 0.13 -- 72.4 -RRB- 4.6 -LRB- 0.7 -- 67.8 -RRB- Age at operation -LRB- months -RRB- 6.8 -LRB- 1.2 -- 74.9 -RRB- 8 -LRB- 0.9 -- 72 -RRB- Weight at operation -LRB- kg -RRB- 7.1 -LRB- 4.5 -- 18.5 -RRB- 8 -LRB- 3.2 -- 22 -RRB- Operation time -LRB- h -RRB- not available4 .5 -LRB- 2.3 -- 9 -RRB- Data given as median -LRB- range -RRB- No intraoperative complications were recorded in both groups . The operative time for the open group could not be traced anymore . In the LD group the mean operative time was 4.8 h -LRB- range = 2.3 -- 9 h -RRB- . Postoperative events are given in Table 2 . Two patients in the LD group underwent a second operation in the early postoperative period : One because of leakage of the rectal stump , which was treated by laparotomy and ileostomy , and the second had laparoscopy because of suspicion of leakage that could not be confirmed . There was a statistically significant difference between the groups with respect to length of hospital stay -LRB- p < 0.001 -RRB- and time of first oral intake -LRB- p < 0.001 -RRB- . Table 2 . Postoperative eventsOpen Duhamel -LRB- n = 25 -RRB- Laparoscopic Duhamel -LRB- n = 30 -RRB- Postoperative fever 31Leakage of rectum stump01Abscesses00Start of oral feeding -LRB- days -RRB- 5.1 -LRB- 4 -- 8 -RRB- 3.4 -LRB- 2 -- 9 -RRB- Hospital stay -LRB- days -RRB- 7.8 -LRB- 6 -- 13 -RRB- 6 -LRB- 3 -- 15 -RRB- Because of the study design the period of follow-up is different between the two groups . Two patients in the LD group were readmitted for dilatation of the anorectum for stenosis . In one of these patients a rectal spur needed to be transected ; this was performed under laparoscopic control . In this patient initially only one cartridge had been used . Reoperation was carried out in one OD patient and in two LD patients . Although statistically not significant , there was a higher incidence of admission for enterocolitis in the LD group . There were more children with adhesive obstruction and with enuresis in the OD group , but again the differences was not statistically significant -LRB- Table 3 -RRB- . Table 3 . Results at follow-upOpen Duhamel -LRB- n = 25 -RRB- Laparoscopic Duhamel -LRB- n = 30 -RRB- Follow-up -LRB- months -RRB- 87.8 -LRB- 7 -- 211 -RRB- 39.5 -LRB- -- 113 -RRB- Reoperation -LRB- Duhamel -RRB- 12Stenosis02Obstructive ileus30Admission for enterocolitis39Admission for constipation75Incontinence00Enuresis 30 Discussion Hirschsprung 's disease is basically incurable . Even when the proximal transection plane of the bowel shows a normal plexus at pathologic examination , there is no guarantee of a good outcome because the distal rectum is and remains abnormal . The best that surgery can achieve is a delicate balance between constipation and incontinence . More often than not the balance tips in one direction . End points are difficult to set and final results are therefore difficult to evaluate . Hirschsprung 's disease is a relatively rare disease and is heterogeneous in the sense that its extension varies and that it may be part of a syndrome . To obtain a group of patients that was as homogeneous as possible , many variables in the present study were excluded . The disadvantage of that is that the subgroups become smaller which makes it harder to obtain significant differences between the groups . With these limitations in mind , we can conclude that there was no difference in intraoperative complication rate . Although the operative times for patients in the OD group were not available , the operative times for patients in the LD group were long , which emphasizes that the laparoscopic procedure is not simple . The difference in starting time of oral feeding and in postoperative hospital stay were significantly longer in the OD group . The first seems to be the result of bias as the postoperative feeding protocol changed over the years toward faster introduction of feeding . The same may apply to the shorter postoperative hospital stay in the LD group although this is less obvious . There were no significant differences in postoperative complications or in the follow-up end points . However , relatively more patients in the LD group were readmitted for enterocolitis , maybe more rectum is left behind with LD . Better functional results have been reported when a short rectal pouch is left -LSB- 8 -RSB- . Although not statistically different , adhesive bowel obstruction was seen in the OD group only and the same applies for enuresis . The cosmetic results were definitely better in the LD group . Conclusion The laparoscopic variant of the Duhamel procedure is not simple , as reflected by its long operation time . There seems to be no essential difference between the open and the laparoscopic procedure with respect to postoperative complications or functional results at follow-up . Although there is a tendency for a higher enterocolitis rate in the LD group , lower adhesive obstruction and enuresis rates were encountered . There is no doubt that the LD is cosmetically superior . Despite the fact that the transanal approach is becoming more popular in recent years , there certainly remains a place for the laparoscopic Duhamel -- Martin procedure , particularly when extended Hirschsprung 's disease is present .

B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O

aganglionosis hirschsprung duhamel laparoscopy


Bone marrow edema in the knee in osteoarthrosis and association with total knee arthroplasty within a three-year follow-up Objective The purpose of this study was to determine if a correlation exists between magnetic resonance imaging -LRB- MRI -RRB- findings of bone marrow edema -LRB- BME -RRB- in osteoarthrosis -LRB- OA -RRB- of the knee joint and need for total knee arthroplasty -LRB- TKA -RRB- within a follow-up period of 3 years . Introduction Osteoarthrosis -LRB- OA -RRB- is the most common cause of disability among the elderly population -LSB- 1 , 2 -RSB- . OA is a condition where articular cartilage can not maintain homeostasis in response to the forces acting on it . When homeostasis breaks down , there is a wide range of possible biologic responses based on the genetic background of the individual -LSB- 3 -RSB- . These responses may be anabolic or catabolic and involve cartilage , bone , and synovium . The exact pathogenesis of OA and the cause of the pain produced are unclear . OA is classically associated with degradation of the hyaline cartilage around the joint . However , cartilage contains no pain fibers . Other proposed sources of pain production in OA include periarticular structures and the underlying bone -LSB- 3 -RSB- . Several recent studies have examined bone marrow edema -LRB- BME -RRB- lesions and their association with OA -LSB- 1 , 4 -- 10 -RSB- . BME has been defined as an area of low signal intensity on T1-weighted images , associated with intermediate or high signal intensity findings on T2-weighted images . The literature suggests that there are two distinct types of BME . The first type occurs traumatically with injury to a joint and tends to resolve over a period of weeks to months -LSB- 11 -- 14 -RSB- . This type of BME does not appear to have any long-term implications -LSB- 15 , 16 -RSB- . The second type of BME occurs without trauma and may be associated with rapidly progressing osteoarthrosis . Zanetti et al. -LSB- 9 -RSB- suggest a possible link between atraumatic BME and increased pain in OA . Felson et al. -LSB- 7 -RSB- have suggested a possible link between BME lesions on magnetic resonance imaging -LRB- MRI -RRB- and progression of OA findings on MRI over time . Hunter et al. found that bone marrow lesions that enlarge with time are associated with more cartilage loss , compared with bone marrow lesions that stay the same size over time -LSB- 17 -RSB- . Despite the recent literature on BME , the implication of these findings on MRI and how they relate to clinical outcomes is unknown . Most studies have used the subjective complaint of pain as the only clinical correlate . There has been no measure of an objective clinical outcome related to the finding of BME . The purpose of this study was to determine if a correlation exists between MRI findings of BME of the knee joint and the incidence of total knee arthroplasty -LRB- TKA -RRB- within a follow-up period of 3 years . Materials and methods The entire database of knee MRI studies from 1995 -- 1997 -LRB- over 4,000 studies -RRB- conducted at a large urban hospital system was used to select individuals with knee osteoarthrosis -LRB- OA -RRB- . The study was reviewed and approved by the hospital 's institutional review board . An initial random search was conducted within this database to identify two distinct groups of patients . The first group had MRI reports containing the phrase `` knee osteoarthrosis/osteoarthritis , '' and the second group consisted of those containing the phrases `` knee osteoarthrosis/osteoarthritis '' and `` bone edema . '' The search for `` osteoarthrosis/osteoarthritis '' yielded 235 cases for review . The search for `` osteoarthrosis/osteoarthritis '' and `` bone edema '' yielded 146 cases for review . After these two initial groups were identified , a chart review was conducted on all 381 patients to identify and include only those patients who had at least a 3-year clinical follow-up appointment from the time of the MRI study . Subjects were also excluded if the reason for referral to MRI was post-traumatic or post-surgical . An initial review of the images was completed by an experienced musculoskeletal radiologist to exclude any subjects with evidence of recent post-surgical or post-traumatic changes not mentioned in the report . After this chart review and initial radiology review process , there were 38 patients in the OA-only group and 35 in the OA with BME group . The same musculoskeletal radiologist who provided the initial review was blinded to the original interpretation of the MRI studies and the patient outcome , and reviewed all 73 studies . The radiologist was aware of the study hypothesis at the time of interpretation . The radiologist assessed each knee for the presence or absence of BME and assigned each subject into either the BME group or the no-BME group for further evaluation . After this review of the images , there were a total of 25 patients with OA only and 48 with OA and BME . The OA-only group consisted of four males and 21 females , with an age range of 28 -- 75 years , and an average age of 49.3 years . Conventional radiographs consisting of anteroposterior , lateral and sunrise views were available for review with 13 of the 25 patients , 52 % of the group . The OA and BME group consisted of 23 men and 25 women , with an age range of 35 -- 82 years and an average age of 53.5 years . Conventional radiographs , again consisting of anteroposterior , lateral , and sunrise views , were available for review with 33 of the 48 patients , 68.75 % of the group . The conventional radiographs , when available , were reviewed by the musculoskeletal radiologist . Radiographic evidence of OA on the radiographs was assessed using the Kellgren -- Lawrence scale -LSB- 18 -RSB- as follows : NoneDoubtfulMinimalModerateSevere According to this scale , evidence of OA includes -LRB- 1 -RRB- formation of osteophytes on joint margins or on the tibial spine , -LRB- 2 -RRB- periarticular ossicles , -LRB- 3 -RRB- narrowing of joint cartilage associated with sclerosis of the subchondral bone , -LRB- 4 -RRB- small pseudocystic areas with sclerotic walls situated usually in the subchondral bone , and -LRB- 5 -RRB- altered shape of the bone ends -LSB- 18 -RSB- . All patients had dedicated knee MR scans either on a GE 1.5-T magnet -LRB- 23 in the OA-only group or 92 % and 42 subjects in the OA with edema group or 87.5 % -RRB- or a 1.0-T magnet -LRB- 8 % of the OA-only group , two subjects , and 12.5 % of the OA with edema group , six patients -RRB- . MRI films were reviewed and interpreted by the musculoskeletal radiologist for all patients in the study . For each patient , the sagittal proton density sequences -LRB- TR range , 2,666 -- 4,100 ; TE range , 14 -- 33 ; 44 conventional spin echo studies -LSB- ET = 0 -RSB- , 29 fast spin echo studies -LSB- ET = 4 -- 8 -RSB- , 3 - to 5-mm section thickness , 16 × 16 -- 18 × 18 field of view -LSB- FOV -RSB- , 256 × 128 -- 256 image matrix , bandwidth range 16 -- 32 -RRB- , coronal proton density sequences -LRB- TR range , 2,316 -- 3,950 ; TE range , 14 -- 33 ; 44 conventional spin echo studies -LSB- ET = 0 -RSB- ; 29 fast spin echo studies -LSB- ET = 4 -- 8 -RSB- ; 3-mm section thickness ; 16 × 16 -- 18 × 18 FOV ; 256 × 128 -- 256 image matrix ; bandwidth range , 16 -- 32 -RRB- , and coronal fat suppressed T2-weighted images -LRB- TR range , 2,400 -- 3,200 ; TE range , 56 -- 80 ; 3 - to 5-mm section thickness ; 16 × 16 -- 18 × 18 FOV ; 256 × 128 -- 256 image matrix ; bandwidth range , 15.6 -- 16 -RRB- were reviewed . Axial fat suppressed T2-weighted images -LRB- TR range , 3,000 -- 3,600 ; TE range , 56 -- 76 ; 1.5 - to 10-mm section thickness ; 16 × 16 -- 20 × 20 FOV ; 256 × 128 -- 256 ; bandwidth range , 15.6 -- 16 -RRB- were available and reviewed for 69 of the 73 knees . For the four subjects who had no axial T2 imaging available , BME in the patellofemoral joint was not assessed . The medial , lateral , and patello-femoral compartments of the knee joint were assessed . Evidence of OA on MRI was assessed using a modified Noyes arthroscopic classification -LSB- 19 -RSB- as follows : NormalInternal changes only1 -- 49 % loss of articular cartilage50 -- 99 % loss of articular cartilage100 % loss of cartilage with subchondral cortex intact100 % loss of cartilage with ulcerated subchondral cortex The most severe grade cartilage lesion within a compartment was utilized for the grading of that compartment . Also , the highest grade cartilage lesion on either side -LRB- femoral or tibial -RRB- of a compartment was used . The radiologist then assessed each knee MRI for the presence or absence of BME . BME was defined as an area of intermediate or high-signal intensity findings on T2-weighted images . All patients in the BME group were then further classified into three separate , groups based on patterns of BME . Type I was termed `` focal '' and contained a small area of edema adjacent to a cartilage defect -LRB- Figs. 1 and 2 -RRB- . Type II was termed `` global '' pattern with marrow edema occupying most or all of a femoral or tibial condyle -LRB- Figs. 3 , 4 , and 5 -RRB- , and type III was termed `` cystic '' and was associated with a subchondral geode with a small area of BME -LRB- Fig. 6 -RRB- . The worst area of edema in a compartment was used in the classification . The presence or absence of meniscal tear was also noted . Fig. 1Focal edema with a total knee joint replacement in a 51-year-old female patient . The radiograph demonstrated moderate loss of cartilage joint space medially and spurring of the tibial spines . Coronal fast fat suppressed T2-weighted image -LRB- TR 3000/TE 76/256 × 192 -RRB- shows the loss of hyaline cartilage and a small focal area of edema in the medial aspect of the medial femoral condyle -LRB- arrow -RRB- Fig. 2Focal edema , no total knee joint replacement , in a 58-year-old male patient . Coronal fast fat suppressed T2-weighted image -LRB- TR 3000/TE 56/256 × 192 -RRB- shows extrusion of the medial meniscus -LRB- curved arrow -RRB- and small adjacent areas of focal marrow edema -LRB- straight arrows -RRB- . The medial meniscus has a degenerative horizontal cleavage tear approximating the tibial surface . Note also the moderate loss of hyaline cartilageFig . 3Global edema with a total knee joint replacement in a 65-year-old male patient . The radiograph demonstrated absence of joint space in the medial and lateral compartments , and irregularity of the subchondral bone plate of the lateral femoral condyle . Coronal fast fat-suppressed T2-weighted image -LRB- TR 3000/TE 72/256 × 192 -RRB- through the knee shows extensive edema in the lateral femoral and tibial condyles , extending into the metaphyses -LRB- straight arrows -RRB- . Note also the small extruded body of the degenerative and torn lateral meniscus -LRB- curved arrow -RRB- Fig. 4Global edema with a total knee joint replacement in a 72-year-old male patient . The radiograph demonstrated loss of cartilage joint space within the lateral compartment . Coronal fast fat-suppressed T2-weighted image -LRB- TR 3200/TE 72/256 × 192 -RRB- shows extensive edema in the femoral and tibial condyles -LRB- arrows -RRB- Fig. 5Global edema , no total knee joint replacement , in a 58-year-old male patient . Coronal fast fat suppressed T2-weighted image -LRB- TR 3000/TE 76/256 × 256 -RRB- through the knee shows extensive edema in the lateral tibial condyle and edema in some of the lateral femoral condyle -LRB- arrows -RRB- . Note also the almost complete absence of hyaline cartilageFig . 6Cystic pattern with a total knee joint replacement in an 82-year-old female patient . The radiograph demonstrated subchondral lucency consistent with a geode and irregularity of the adjacent subchondral bone plate . Coronal fast fat-suppressed T2-weighted image -LRB- TR 3000/TE 56/256 × 192 -RRB- shows complete loss of hyaline cartilage on the medial femoral condyle and adjacent moderate subchondral cystic areas consistent with geodes , and the adjacent bone marrow edema -LRB- arrows -RRB- . Note also the extruded body of the medial meniscus containing a degenerative horizontal cleavage tear -LRB- curved arrow -RRB- Generalized estimating equations -LRB- GEE -RRB- were used to determine which factors were related to receiving a TKA . There were eight subjects who had bilateral knee MRIs . GEE takes into account the correlation within an individual who had both knees involved , whereas a general linear model assumes that all observations are independent and does not allow for multiple observations from one individual . A multivariable logistic regression model using generalized estimation was also used to adjust for the age of the patients and to determine if the results were still significant after accounting for the age differences . Results There were 65 subjects in this study , with a total of 73 knees . After the final classification by the radiologist , there were 48 knees in the group with BME . There were a total of 15 knees or 31.125 % in this group that had a TKA . There were 34 knees with a focal pattern of BME , 12 with a global pattern , and two with a cystic pattern . Of those with a focal pattern , 20.5 % -LSB- 7 -RSB- had a TKA -LRB- Fig. 1 -RRB- . For those with a global pattern , 58.3 % -LSB- 7 -RSB- had a TKA -LRB- Figs. 3 and 4 -RRB- , and for those with a cystic pattern , 50 % -LSB- 1 -RSB- had a TKA -LRB- Fig. 6 -RRB- . These results are detailed in Table 1 . Table 1Patterns of edema and percentage of those who subsequently received TKAPattern of edemaTotal numberNumber with TKAPercentage with TKA -LRB- % -RRB- Focal34720 .5 Global12758 .3 Cyst2150All patterns of edema481531 .2 None2528 There were 25 knees in the group with no BME . There were a total of two knees or 8 % of those without BME who had a TKA -LRB- Fig. 7 ; see Table 1 -RRB- . Fig. 7No bone marrow edema with a total joint replacement in a 66-year-old female patient . Coronal fast fat-suppressed T2-weighted image -LRB- TR 2500/TE 80/256 × 256 -RRB- shows almost complete loss of hyaline cartilage in the medial compartment and an extruded , degenerative torn medial meniscus . Note the absence of marrow edema For statistical purposes , secondary to the small numbers of subjects in each subgroup , subjects were classified using the modified Noyes scale -LRB- 0 , 1 , 2a , 2b , 3a , and 3b -RRB- , and the data was grouped as cartilage damage less than 50 % -LRB- 0 , 1 , 2a -RRB- and cartilage damage greater than or equal to 50 % -LRB- 2b , 3a , 3b -RRB- . For all three compartments of the knee , there were no statistical differences in rates of TKA between the groups that had less than 50 % damage and the groups that had greater than 50 % damage -LRB- see Table 2 -RRB- . Table 2Cartilage loss seen on MR , as graded by the modified Noyes scale , and its relationship to the occurrence of TKAVariableNo TKAYes TKAOR95 % CIp ValueMedial cartilage loss < 50 % 17 -LRB- 30 % -RRB- 2 -LRB- 12 % -RRB- 2.770.71 -- 10.720.14 Medial cartilage loss ≥ 50 % 39 -LRB- 70 % -RRB- 15 -LRB- 88 % -RRB- Lateral cartilage loss < 50 % 42 -LRB- 75 % -RRB- 10 -LRB- 59 % -RRB- 2.060.74 -- 5.700.16 Lateral cartilage loss ≥ 50 % 14 -LRB- 25 % -RRB- 7 -LRB- 41 % -RRB- PF cartilage loss < 50 % 15 -LRB- 28 % -RRB- 3 -LRB- 19 % -RRB- 1.680.45 -- 6.290.44 PF cartilage loss ≥ 50 % 38 -LRB- 72 % -RRB- 13 -LRB- 81 % -RRB- For statistical analysis of the radiographs using the Kellgren -- Lawrence scale , subjects who had scores of 0 -- 2 -LRB- none , doubtful , or minimal -RRB- were compared with subjects who had a score of 3 -- 4 -LRB- moderate , severe -RRB- to assess for statistical difference in the occurrence rate of TKA . Those subjects who had a Kellgren -- Lawrence score of 3 -- 4 were no more likely to have a TKA performed than those who had a score of 0 -- 2 -LRB- see Table 3 -RRB- . Table 3Radiographic findings , as graded by the Kellgren -- Lawrence scale , and their relationship to occurrence of TKAScoreNo knee replacement -LRB- N = 35 -RRB- Knee replacement -LRB- N = 11 -RRB- OR95 % CIp Value0 -- 28 -LRB- 23 % -RRB- 1 -LRB- 9 % -RRB- 1.00060.9996 -- 1.00160.233 -- 427 -LRB- 77 % -RRB- 10 -LRB- 91 % -RRB- Table 4 shows the results of the subjects with BME , using the patterns of edema , compared to those without BME . Subjects who had BME of any pattern type were 5.48 times as likely to have a TKA when compared to subjects with no BME -LRB- p = 0.05 -RRB- . Upon further investigation , subjects with a global pattern of BME were 7.63 times as likely to have a TKA compared to subjects with focal , cyst , or no BME -LRB- p = 0.004 -RRB- . Subjects with global BME were 15.21 times as likely to get a TKA when compared to subjects without BME -LRB- p < 0.001 -RRB- . Table 4Comparison of bone marrow edema patterns and their relationship to occurrence of TKAVariableNo TKAYes TKAOR95 % CIp ValueNo BME23 -LRB- 41 % -RRB- 2 -LRB- 12 % -RRB- 5.480.98 -- 30.680.05 BME of any pattern33 -LRB- 59 % -RRB- 15 -LRB- 88 % -RRB- Global BME5 -LRB- 9 % -RRB- 7 -LRB- 41 % -RRB- 7.631.89 -- 28.340.004 All other patterns -LRB- focal , cyst , none -RRB- 51 -LRB- 91 % -RRB- 10 -LRB- 59 % -RRB- Global BME5 -LRB- 18 % -RRB- 7 -LRB- 78 % -RRB- 15.212.38 -- 97.10 < 0.001 No BME23 -LRB- 82 % -RRB- 2 -LRB- 22 % -RRB- First , no bone marrow edema is compared with BME of any pattern . Next global BME is compared to all other patterns , including no edema . Finally , global BME is compared with no BME . Table 5 demonstrates the results of a univariate comparison between subjects with BME and without BME , and their scores on the modified Noyes and the Kellgren -- Lawrence classifications . For the medial compartment only , subjects who had high scores on the Noyes and Kellgren -- Lawrence scales tended to have BME , whereas those subjects with lower scores on the Noyes and Kellgren -- Lawrence scales tended to have no BME . Table 5Univariate comparisons between those knees with BME and those without BME -LRB- t tests -RRB- VariableScoreNo BMEBMEp ValueModified Noyes score lateral compartment0 -- 2a20 -LRB- 80 % -RRB- 32 -LRB- 67 % -RRB- 0.2322 b -- 3b5 -LRB- 20 % -RRB- 16 -LRB- 33 % -RRB- Modified Noyes score medial compartment0 -- 2a11 -LRB- 44 % -RRB- 8 -LRB- 17 % -RRB- 0.0122 b -- 3b14 -LRB- 56 % -RRB- 40 -LRB- 83 % -RRB- Modified Noyes score patellofemoral compartment0 -- 2a4 -LRB- 17 % -RRB- 14 -LRB- 31 % -RRB- 0.1932 b -- 3b20 -LRB- 83 % -RRB- 31 -LRB- 69 % -RRB- Kellgren -- Lawrence score lateral compartment0 -- 213 -LRB- 100 % -RRB- 26 -LRB- 79 % -RRB- 0.0713 -- 40 -LRB- 0 % -RRB- 7 -LRB- 21 % -RRB- Kellgren -- Lawrence score medial compartment0 -- 29 -LRB- 69 % -RRB- 11 -LRB- 33 % -RRB- 0.0273 -- 44 -LRB- 31 % -RRB- 22 -LRB- 67 % -RRB- Kellgren -- Lawrence score patellofemoral compartment0 -- 25 -LRB- 42 % -RRB- 11 -LRB- 33 % -RRB- 0.6063 -- 47 -LRB- 58 % -RRB- 22 -LRB- 67 % -RRB- The presence of a meniscal tear did not correlate with subsequent TKA . There was no significant difference in the gender between the group that received a TKA and those that did not . The group of subjects who had a TKA were 12.6 years older than those who did not have a TKA -LRB- p = < 0.001 -RRB- . In this study , the odds of having a TKA increase by about 1.11 times for each year increase in age . A multivariable logistic regression model using generalized estimation was performed to account for the age difference in the groups and assess whether or not the results were still significant despite the age difference . Table 6 displays these results and demonstrates that , after accounting for the age difference , subjects who had BME of any pattern type were 8.95 times as likely to have a TKA when compared to subjects with no BME -LRB- p = 0.016 -RRB- . Subjects with global BME were 13.04 times as likely to get a TKA when compared to subjects without BME -LRB- p < 0.01 -RRB- . Subjects with a global pattern of BME were 5.45 times as likely to have a TKA compared to subjects with focal , cyst , or no BME -LRB- p < 0.05 -RRB- . Table 6Results of the multivariable logistic regression model using generalized estimation to account for the age difference in the groups that received a TKA versus those that did not Outcome : TKAVariableOR95 % CIp-valueModel 1BME versus no BMEf8 .951.49 -- 53.680.0164 Age1 .131.07 -- 1.20 < 0.0001 Model 2Global BME versus No BME13 .042.06 -- 82.580.0064 Age1 .060.99 -- 1.150.11 Model 3Global BME versus all other patterns -LRB- focal , cyst , and no edema -RRB- 5.451.02 -- 28.960.0467 Age1 .1071.05 -- 1.170.0002 Discussion BME has previously been noted in the musculoskeletal system in osteoarthrosis and other conditions -LSB- 1 , 4 -- 11 , 13 , 14 , 20 -RSB- . Felson and colleagues have examined BME and its relation to progression of knee osteoarthrosis and noted that BME is a potent risk factor for structural deterioration in knee osteoarthrosis -LSB- 1 , 7 , 17 -RSB- . Its relation to progression is explained in part by its association with limb alignment . In two of his studies , medial bone marrow lesions were seen mostly in patients with varus limbs and lateral lesions were seen mostly in those with valgus limbs -LSB- 7 , 17 -RSB- . Link and colleagues -LSB- 4 -RSB- reviewed MR findings in osteoarthrosis and noted that cartilage lesions , BME patterns , and meniscal and ligamentous lesions were frequently demonstrated as MR changes in patients with advanced osteoarthrosis . However , in this study , there was no significant correlation between MR and clinical findings . A recent study conducted by Kornaat et al. -LSB- 21 -RSB- examined multiple imaging findings and their association with clinical symptoms . Their results suggest that only findings of a large-joint effusion or the presence of an osteophyte in the patellofemoral compartment were associated with pain and/or stiffness . They found no association between BME and symptoms of pain or stiffness . Three studies have reviewed the MR appearances with histopathology findings -LSB- 6 , 9 , 10 -RSB- . Bergman and colleagues in their study found that subchondral bone marrow changes were present in seven of nine patients undergoing total knee replacement -LSB- 10 -RSB- . Histopathologically , those regions showed focal areas where fibrous tissue replaced fatty marrow in the subchondral trabecular space . Zanetti and colleagues reviewed the histopathological findings in 16 patients who had MR before total knee replacement . The BME pattern consisted of normal tissue and a smaller proportion of several abnormalities including bone marrow necrosis , bone marrow fibrosis , abnormal trabeculae , BME , and bone marrow bleeding . They concluded that a BME pattern in knees with osteoarthrosis represents a number of non-characteristic histological abnormalities -LSB- 9 -RSB- . Nolte -- Ernstein and colleagues examined the correlation between MR and histological findings of degenerative bone marrow lesions in experimental osteoartrhosis models in canine knee joints -LSB- 6 -RSB- . In these experimental lesions , the histopathology revealed 21 osteosclerotic lesions and 5 intraosseous cysts . Histopathological findings showed different degrees of osteosclerosis associated with bone marrow degeneration . Cystic lesions were of two types : subchondral epiphyseal cysts and synovial cysts within a large tibial osteophyte . High signal intensity on T2-weighted images and decreased signal intensity on T1-weighted images indicated high fluid content . None of these prior studies specifically looked at the BME pattern on MR. Our classification of the patterns into global , focal , cystic , and absence of edema is an attempt to subdivide the presence or absence of edema in osteoarthrosis . However , this attempt is limited by the absence of histopathological findings . We were surprised by the significantly increased risk of knee joint replacement with the global pattern of BME in relation to the other patterns . It appears that the more extensive and intense the BME , the more likely it is for the patient to have symptoms . The global pattern of BME was the best predictor of risk of TKA within 3 years , as those subjects with the global pattern were over five times as likely to receive a TKA when compared to those with any of the other patterns and over 13 times as likely to have a TKA when compared with subjects with no BME , after accounting for the age difference . We were also surprised by the lack of association between cartilage loss and the likelihood of total knee replacement . Intuitively , one would think that the greater the cartilage loss , the more likely the possibility of total knee replacement . However , Link and colleagues -LSB- 4 -RSB- noted that clinical findings showed no significant correlation with the extent of cartilage loss on MR imaging . In this study , the lowest scores for pain and function loss were found in patients without cartilage lesions . However , the highest scores for pain , stiffness , and function loss were found in patients with less than 50 % cartilage loss . The lowest scores for stiffness were found in patients with more than 50 % cartilage loss and full-thickness lesions . These findings further support the theory that cartilage loss may not be the primary source of pain in patients with OA of the knee . We did find , in the medial compartment only , that subjects with high grades of cartilage loss or advanced degenerative changes on radiographs tended to have some degree of BME . The lack of association between cartilage loss and the likelihood of TKA in our study could be a reflection of the limitations of the Noyes classification system . However , other investigators have also found that radiographic signs of cartilage loss may not relate to the degree of clinical symptoms . As mentioned above , Link and colleagues found no correlation with the extent of cartilage loss on MR and clinical findings . In their study , they also used a modified Noyes classification system -LSB- 4 -RSB- . Kornaat et al. also found no correlation between the extent of cartilage damage seen on MR imaging and clinical symptoms of pain and stiffness . They used a grading scale based on the maximum diameter of cartilage defects and the depth of the lesion based on the percentage of cartilage loss -LSB- 21 -RSB- . In clinical practice , OA is associated with the radiographic findings of joint space loss and subchondral sclerosis , presumably secondary to cartilage loss that results in pain . However , as stated earlier , there are no pain fibers in hyaline cartilage -LSB- 3 -RSB- . Furthermore , many patients have pain out of proportion to their radiographic findings . Our study may provide an insight into another possible mechanism for pain production in OA of the knee . While not every patient with OA warrants an MR scan , those patients without the classic presentation may benefit . We did find that patients who had a TKA were 12.6 years older than those who did not have a TKA . Patients who are older are more likely to have OA and , in particular , more severe OA . Surgical replacement of the knee is more likely to occur in an older patient with OA than a younger patient with the same severity of OA . After further statistical analysis , we however found that our BME results were still significant despite the differences in age . This paper has several limitations . Most patients who have a TKA do not get a pre-operative MR , and therefore , we may be dealing with a pre-selected population . What we have called `` BME '' on MR may not be true edema but may relate to other histologic findings as noted earlier . Our numbers are also small , and we had to group some of our subsets together for statistical analysis . Only one musculoskeletal radiologist was involved in the review of the radiology . There was also no arthroscopic correlation for cartilage defects or presence of meniscal tears . Our study is limited by the fact that it is retrospective . To generate a group of MR scans to review , we had to use a keyword search to identify potential subjects . We would have obviously missed all scans where the specific terminology `` bone edema '' or knee `` osteoarthrosis/osteoarthritis '' was not utilized . However , we feel that this is a relatively minor limitation , as we were able to generate 381 cases for review . Another potential limitation in the retrospective study design is the possibility of missing subjects who received follow-up at a different institution or those whose symptoms resolved without treatment . In summary , we reviewed a series of knees in patients with osteoarthrosis and evaluated the pattern of BME , cartilage loss , radiographic findings when available , and the incidence of total knee joint replacement within a 3-year follow-up . Subjects with any bone marrow edema pattern were more likely to have a total knee joint replacement compared to subjects with no bone marrow edema . The worst prognostic pattern was the global pattern of bone marrow edema . Subjects who had a total knee replacement were also older than those who did not . However , even allowing for age , the global pattern of BME remained the variable with the highest statistically significant association with the incidence of total knee replacement .

B I I O O O O B O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O B O O O O O O O O O O B I I O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O B I I O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

osteoarthrosis
bone marrow edema
total knee arthroplasty