desmoid tumors ( dts ) , also called aggressive fibromatosis , are very rare with an estimated incidence of 25 cases per million of inhabitants in european countries [ 1 , 2 ] .
dts lack the capacity to metastasize but may behave in a locally aggressive fashion and possess a high risk of local recurrence despite adequate surgical resection with negative margins [ 1 , 3 ] .
dts can develop in any musculoaponeurotic structure and they may be located at virtually any anatomical site .
the principal sites of involvement for extra - abdominal fibromatosis are the shoulder , chest wall and back , thigh and head and neck region .
intra - abdominal fibromatosis arises in the mesentery or pelvis while abdominal tumors arise from musculoaponeurotic structures of the abdominal wall , especially the rectus and internal oblique muscles and their fascial coverings [ 4 , 5 ] . in the surgically treated patients who experience
recurrence of dt ( local recurrence rates are about 2565% ) a wide excision is needed in some cases .
synthetic meshes often used in extensive abdominal wall reconstruction may present with complications , including infection , bowel adhesion , extrusion , and fistula according to the prosthetic material used .
a prosthetic material with more favorable properties than traditional mesh could have a major effect on surgical practice and patient outcomes , avoiding chronic inflammation and resisting infection after implantation .
considering baumann 's description of the ideal biomaterial for abdominal wall repair , our choice was directed towards a not cross - linked acellular dermal matrix ( adm ) which remodels into host tissue .
the matrix serves as a scaffold and becomes rapidly revascularized and infiltrated with host cells , avoiding fibrotic reaction and encapsulation as well as seroma formation .
the revascularization of biological matrices is thought to promote access of host immune cells as well , thereby providing further resistance to future infections .
this is the first report about the use of the not cross - linked dermal matrix egis in a case of abdominal wall recostruction after extensive dt resection .
in 2008 , a 37-year - old woman underwent , in a different hospital , exeresis of a neoformation in the epigastric region of the abdominal wall and reinforcement with small prosthetic mesh .
she reported an appendectomy , two pregnancies with cesarean births and a voluntary interruption of pregnancy . in 2014 , a recurrence occurred in the context of the rectus abdominis in the left iliac fossa .
the patient therefore underwent tamoxifen therapy for 1 year followed by 3 months of neoadiuvant chemotherapy for progressive disease . in september 2015 , magnetic resonance imaging ( mri )
1a , c , e ) , which revealed a marked progression of the disease ( calculated size 18  10  6.4 cm ) .
after discussions at our multidisciplinary sarcoma meeting , the group decision was to treat the patient surgically .
one month later , the woman had a surgical resection through a suprapubic transverse incision .
the abdominal flap was cranially detached ; the neoformation invaded completely the left abdominal rectus muscle and partially oblique muscles with an extension of approximately 30  20 cm ( fig .
1a , 2a ) . the rectus muscle and a large portion of the oblique and transverse muscles were removed  en bloc  with 1 cm of healthy margin from the mass ( fig .
intraperitoneal drainage was placed , and a wide continuous solution was adopted in the left abdomen .
the not cross - linked porcine dermal matrix egis ( decomed , venice , italy ) 30  20 cm , 1.5 mm thick , was hydrated for 10 min in sterile saline solution and then secured with interrupted absorbable suture ( vicryl 2/0 ) to the fascia and abdominal wall muscles ( fig .
we performed caudal mobilization of the abdominal flap and then dermolipectomy of the superfluous integument .
the postoperative course was uneventful and the patient was discharged on the 8th postoperative day .
there was no evidence of recurrence of the tumor or incisional hernia at 12 months of follow - up ( fig .
1b , d , f ) and the membrane turned out to be completly incorporated with the sourrounding tissues .
histological examination of the resected specimen ( 17  10  6 cm ) revealed tumor - free margins and a whitish lesion with increased thickness and fibrous appearance , which had almost completely invaded the abdominal muscle .
the diagnosis was confirmed by the presence of spindle - cellular tumors which had immigrated through muscle tissues as shown by nuclear -catenin staining .
dfs are neoplasms with infiltrating growth and with a tendency toward local recurrences ; nevertheless , they lack metastatic potential .
although the morphologies of these tumors have been well characterized , their nature and pathogenesis have remained obscure for many years [ 6 , 9 ] . according to the literature
, the median age at the diagnosis of dfs is about 35 years , and the majority of patients are women . in particular , patients between puberty and the fourth decade of life tend to be female , and in these patients the abdominal wall is the preferred site of involvement . supposed risk factors of desmoids are previous surgical interventions , pregnancy , and hormonal treatment with estrogens . because the tumor biology is notoriously unpredictable , periods of rapid tumor growth can be followed by stability or even regression .
the treatment with tamoxifen , as well as chemotherapy and radiation , is controversial , since the long - term clinical improvement is minimal , while surgical excision should be performed only when absolutely necessary .
abdominal wall integrity after full - thickness surgery can be restored with direct suture , but the occurrence of postoperative incisional hernia is highly reported .
for this reason one - stage reconstruction with prosthetic abdominal wall reinforcement increases the chance of definitive cure , enhancing the patient 's perceived quality of treatment .
randomized controlled trial observed a double rate of hernia recurrence in the primary suture group compared with the mesh reinforcement group .
the meshes used are classified according to their gap size which defines the porosity of the mesh and consequently the behavior with surrounding tissue , but a common tendency to develop postoperative complications was reported with all these devices .
synthetic meshes are usually associated with an increased risk of extrusion , adhesion , and following obstruction and enterocutaneus fistula formation , especially when placed in an overlay fashion .
moreover , patients who have had radiation to the abdominal wall prior to reconstruction are at increased risk for wound healing complications and subsequent mesh exposure . for that reason , butler et al .   recommend avoiding synthetic meshes in patients with radiated abdominal walls .
the advent of biological matrices has added a valuable option to the field of abdominal wall reconstruction .
the inherent ability of biological matrix to turn into patient self - tissue , and therefore resist infection , allows to implant it in direct contact with the bowel , resulting in fewer adhesions than prosthetic mesh [ 8 , 12 ] .
these bioprosthetic devices , deriving from human or animal dermis , are chemically and enzymatically cleaned to remove all cellular components while maintaining the extracellular matrix , which can be cross - linked or not .
it is hypothesized that cross - linking treatment adds strength to the matrix , theoretically resulting in lower rates of hernia recurrence as compared to non - cross - linked products .
in contrast butler et al .   in a comparative study had not appreciated any mechanical differences between cross - linked and non - cross - linked matrices .
moreover cross - linked matrices revealed delayed revascularization and higher percentage of adhesions resulting in poor integration regarding non - cross - linked adms . despite the great advantages reported about the biological matrices , the high price that distinguishes them , ranging from usd 8.60/cm to usd 22.00/cm , remains a high deterrent to their use .
one variation of the biological materials , egis , has not been described yet in the literature for abdominal wall reconstruction after tumor excision .
egis ( decomed , venice , italy ) is a dry porcine adm , non - cross - linked , without any chemical preservative ; its very competitive price , about half of the aforementioned costs , allows us to choose the benefits of a biological matrix with the advantage of controlled expense .
we report for the first time the successful use of egis in a complex abdominal wall reconstruction following the resection of a large dt .
the matrix was well accepted without any postoperative complications and no evidence of recurrence of the tumor or incisional hernia has been reported 12 months later . in conclusion
, this single - case experience makes us to consider the biological matrix egis , as well as other adms , an ideal alternative to synthetic mesh , mainly in cases with a potential risk of infection .
the protocol for data collection of this case has been approved by the institute 's committee and complies with the helsinki guidelines for human studies .
 desmoid tumor is a rare monoclonal fibroblast proliferation that is regarded as benign . 
 the clinical management of desmoid tumors is very complex and requires a multidisciplinary approach because of the unpredictable disease course . for those cases localized in the anterior abdominal wall , symptomatic and unresponsive to medical treatment , radical resection and reconstruction with a prosthetic device 
 are indicated . 
 we present here a case of desmoid fibromatosis of the left anterolateral abdominal wall with a marked increase of the mass that required a large excision followed by reconstruction with biological matrix . 
 the fact that it can be incorporated in patient tissue without a fibrotic response and that it can resist future infections , together with a very competetive price , made the new collagen matrix egis our first choice . 