while the term  textiloma  is used to describe a mass lesion consisting of surgical sponge , the term  gossybipoma  is reserved for both the mass of sponge and the foreign body reaction around it . these pathologies can mimic other common spinal mass lesions such as hematoma , abscess , soft tissue tumor , etc . their presentation is well known but varies with each case due to different kinds of reactions of body . in literature , 46 cases of gossybipoma involving the spine have been reported;[13419 ] however , it is thought to be more than this number because of medico - legal issues . in this report , we present a case of paravertebral gossybipoma , with a short review of the clinical presentation , radiologic findings and differential diagnosis of these lesions . a 40-year - old woman presented with a history of spinal operation for l4l5 lumbar disk herniation before 8 months and got admitted with non - purulent serous leakage from a small ( 5 mm ) detachment in the surgical wound . the wound was minimal erythematous at the detachment site , but there was no tenderness , swelling or fluctuation . there was no fever , and routine laboratory tests including complete blood count , erythrocyte sedimentation rate , c - reactive protein and blood biochemistry were all normal . microbiologic investigations of the serous leakage revealed no pathogens . while waiting for the microbiological results , treatment with first - generation cephalosporin was started and continued for 4 days , and the serous leakage stopped immediately with secondary healing of the wound in a 1-week period . however , the patient 's same complaints recurred , and thus she got admitted again to our clinic . a computed tomography ( ct ) of the lumbar vertebrae revealed a hyperdense mass lesion located in the left side of the previous operation site . magnetic resonance imaging ( mri ) showed a mass lesion in the left paravertebral area , which was hypointense on t1- and t2-weighted images , with peripheral hyperintense ring in t2-weighted images . mri post - contrast images showed ring enhancement of the lesion [ figure 1 ] . lumbar imaging of our case revealed a paravertebral mass lesion located in the left side of the previous operation site ( arrows ) . ( a ) axial ct scan , ( b ) axial post - contrast enhanced mri , ( c ) sagittal t2-weighted mri the patient was operated by lumbar midline reincision , and the exploration of the left paravertebral area revealed a retained sponge . the sponge was found adherent to the surrounding soft tissue by the new formed fibrotic tissue , which required individual dissection of these fibrotic attachments . histopathologic examination revealed mononuclear cell infiltration and fibrosis formation around the retained sponge [ figure 2 ] . the patient 's complaints showed improvement with no neurologic deficits , and the patient was discharged on postoperative day 3 without complications . a photomicrograph shows the mononuclear cell infi ltration and fi brosis formation around the retained sponge ( h and e , 200 ) many different kinds of hemostatic agents  absorbable and non - absorbable  are used to control intraoperative bleeding in neurosurgical operations . non - absorbable materials include various forms of cotton pledgets and synthetic hemostats , which should be removed before surgical closure . retained surgical sponges can be found following abdominal , gynecologic , urologic , thoracic , orthopedic or neurosurgical procedures . they are encountered in abdominal and thoracic cavities more commonly but they are also reported after extremity and spinal surgeries . a retained surgical sponge is thought to be a common entity ; however , due to the medico - legal issues , only a few cases in the literature have been reported . while the term  textiloma  is used to describe a mass lesion consisting of surgical sponge , the term  gossybipoma  is reserved for both the mass of sponge and the foreign body reaction around it . in the literature , there are 46 reported cases of gossybipoma after spinal surgery since 1965.[13419 ] in these reports , patients had presented mostly with complaints of back pain , common motor weakness and/or sensory deficits in neurologic examination , with no infectious findings , at which the placement of surgical sponge occurred at least a couple years ago before the admission.[151719 ] on the other hand , some cases admitted with fluid leakage after only a short time of the first operation . in our case , the patient presented with sterile serous leakage from the operation wound , 8 months after the previous operation . after surgery , the body gives two types of foreign body reactions against retained sponges : ( 1 ) the exudative type tissue reaction , which leads to acute abscess formation , with a tendency to form fistulas through the skin and ( 2 ) aseptic fibrous tissue reaction , which involves slow adhesion formation , such as encapsulation and granuloma formation . while the time interval to clinical presentation is short with the exudative type tissue reaction , it ranges to even decades after surgery with aseptic fibrous tissue reaction . surgical sponges with radiopaque markers are used now in most of the medical centers . due to this imaging characteristic of the gossybipomas , plain radiographs and/or had reported 13 patients with gossybipomas in thorax and abdomen , and remarked that the radiopaque marker inside the gossybipoma was seen in only nine patients ( 69.2% ) and even then did not always lead to diagnosis . in our case , the gossybipoma was revealed in ct scans as a hyperdense mass lesion , although it was not diagnostic for this lesion . because the differential diagnosis of paraspinal lesions in patients with history of spinal operations include hematomas , abscess or residual / recurrent tumors , mri with intravenous contrast enhancement is known to be the best radiologic investigation modality in these situations [ table 1 ] . kim et al . stated that mri usually shows a well - defined mass with a fibrous capsule that exhibits low signal intensity on t1-weighted images compared with the signal intensity of the paravertebral back muscles , high signal intensity in the center with hypointense rim on t2-weighted images , and strong peripheral enhancement in post - contrast images . on the other hand , mri of our case demonstrated a mass lesion , which was hypointense on both t1- and t2-weighted images , with peripheral hyperintense ring in t2-weighted images and peripheral enhancement in post - contrast images . accordingly , we believe that despite the importance of the mri in the diagnosis of gossybipoma lesions , the definitive diagnosis must be mainly aided by the high suspicion profile of the physician and the intraoperative findings . in patients with the history of spinal operation , gossybipomas should always have a place in the differential diagnosis of newly found lesions , as it is believed that they are much more common than they are reported . however , no pathognomic radiologic characteristics are defined for these lesions . for this reason , the definitive diagnosis must be mainly aided by the high suspicion profile of the physician and the intraoperative findings . thus , it must be remembered that careful inspection of the surgical field before closure is still an important basic rule in surgery .
spinal or paraspinal retained surgical sponges ( gossybipoma or textiloma ) are rare incidents and mostly asymptomatic in chronic cases , but can be confused with other masses such as a hematoma , an abscess or a tumor . in chronic cases 
 , the presentation can be as late as decades after the initial surgery ; however , some gossybipomas cause infection or abscess formation in the early stages . 
 the authors report a 40-year - old woman with a history of operation for lumbar disk herniation before 8 months , and got admitted with a complaint of serous fluid leakage from the operation wound . in this report 
 , the authors discuss the clinical presentation , the radiologic findings and the differential diagnosis of gossybipoma .