desmoplastic small round cell tumor ( dsrct ) is a very rare and aggressive mesenchymal cancer , characterized by intraperitoneal masses without an apparent organ of origin . it resembles other small round cell tumors   as described by gerald and rosai in 1989 . it occurs mainly in children , young adults , and males [ 5 , 6 ] with an average age of 22 years . histologically , it is characterized by clustering of small round cells separated by desmoplastic stroma . in immunohistochemistry ( ih ) chemotherapy and radiotherapy cause temporary improvement and are therefore essential for surgical cytoreduction for increasing survival time . a 22-year - old male presented with a 3-month history of intensive backaches and weight loss . it evolved into intestinal semiocclusion . on computed tomography ( ct ) , performed on august 18 , 2009 , 1 ) , extending to the umbilical region , with peritoneal implants and the liver capsule ( 7.0 cm ) . a laparoscopy with biopsy was done , confirming an unresectable retroperitoneal mass . histology and ih studies ( table 1 ) confirmed the diagnosis of dsrct . on september 19 , 2009 , with a performance status ( ps ) of 3 , m and cisplatin 60 mg / m on day ( d)1 ] , as available from the public service . after the 3rd cycle of chemotherapy , abdominal ct still showed a solid heterogeneous mass , but with a reduction of 42% . after the 8th cycle of chemotherapy , on may 3 , 2010 , a new ct scan showed stabilization of the lesions ; however , they remained inoperable . , he had had a survival time of 13 months . a 37-year - old male presented with a 2-month history of poor digestion and weight loss of 7 kg . on clinical examination , a right abdominal tumor mass was found . magnetic resonance imaging ( mri ) confirmed an abdominal lesion , measuring 18.9  16.6 cm , on the periphery of the liver segment vi . a chest ct scan was normal . at exploratory laparotomy , on october 7 , 2008 , a tumor attached to the liver , invading the splenic hilum , omentum , and mesenteric region was found . he started chemotherapy ( carboplatin auc5 , paclitaxel 180 mg / m , and bevacizumab 7.5 mg / kg ) on november 18 , 2008 , for 21/21 days , with a covenant provided by private health insurance . after the 3rd round of chemotherapy , on january 16 , 2009 , mri already showed partial remission ( 78.6% reduction ) . after the 8th cycle , on may 12 , 2009 , a presurgical positron emission tomography ( pet ) reassessment was performed . interestingly , pet showed physiological distribution of f-18-fluorodeoxyglucose ( fdg ) without identifying any uptake ( fig . 3 ) . a concomitant ct scan showed tumor infiltration of the hilum , hepatic parenchyma , and peritoneal implants ( fig . two months after that , there was a clinical and liver function worsening due to tumor progression and compression of the biliary tract . this scheme was discontinued after the 10th cycle on march 30 , 2010 ( 4.9-cm tumor ) due to more frequent occurrences of neutropenia . chemotherapy was then initiated with cyclophosphamide 50 mg / day , oral , and bevacizumab ; this regimen was maintained until november 16 , 2010 , when it was suspended because of worsening of the patient 's clinical state and laboratory findings . he remained in hospice care until his death on july 22 , 2011 , due to neoplastic cachexia and hepatic encephalopathy . a 22-year - old male presented with a 3-month history of intensive backaches and weight loss . it evolved into intestinal semiocclusion . on computed tomography ( ct ) , performed on august 18 , 2009 , 1 ) , extending to the umbilical region , with peritoneal implants and the liver capsule ( 7.0 cm ) . a laparoscopy with biopsy was done , confirming an unresectable retroperitoneal mass . histology and ih studies ( table 1 ) confirmed the diagnosis of dsrct . on september 19 , 2009 , with a performance status ( ps ) of 3 , m and cisplatin 60 mg / m on day ( d)1 ] , as available from the public service . after the 3rd cycle of chemotherapy , abdominal ct still showed a solid heterogeneous mass , but with a reduction of 42% . after the 8th cycle of chemotherapy , on may 3 , 2010 , a new ct scan showed stabilization of the lesions ; however , they remained inoperable . a 37-year - old male presented with a 2-month history of poor digestion and weight loss of 7 kg . on clinical examination , a right abdominal tumor mass was found . magnetic resonance imaging ( mri ) confirmed an abdominal lesion , measuring 18.9  16.6 cm , on the periphery of the liver segment vi . a chest ct scan was normal . at exploratory laparotomy , on october 7 , 2008 , a tumor attached to the liver , invading the splenic hilum , omentum , and mesenteric region was found . he started chemotherapy ( carboplatin auc5 , paclitaxel 180 mg / m , and bevacizumab 7.5 mg / kg ) on november 18 , 2008 , for 21/21 days , with a covenant provided by private health insurance . after the 3rd round of chemotherapy , on january 16 , 2009 , mri already showed partial remission ( 78.6% reduction ) . after the 8th cycle , on may 12 , 2009 , a presurgical positron emission tomography ( pet ) reassessment was performed . interestingly , pet showed physiological distribution of f-18-fluorodeoxyglucose ( fdg ) without identifying any uptake ( fig . 3 ) . a concomitant ct scan showed tumor infiltration of the hilum , hepatic parenchyma , and peritoneal implants ( fig . two months after that , there was a clinical and liver function worsening due to tumor progression and compression of the biliary tract . this scheme was discontinued after the 10th cycle on march 30 , 2010 ( 4.9-cm tumor ) due to more frequent occurrences of neutropenia . chemotherapy was then initiated with cyclophosphamide 50 mg / day , oral , and bevacizumab ; this regimen was maintained until november 16 , 2010 , when it was suspended because of worsening of the patient 's clinical state and laboratory findings . he remained in hospice care until his death on july 22 , 2011 , due to neoplastic cachexia and hepatic encephalopathy . we presented 2 cases in men , 22 and 37 years old , respectively , emphasizing that dsrct occurs predominantly in young males [ 2 , 7 , 9 ] . the common symptoms are abdominal distention or pain , palpable mass , and weight loss   which intensifies with tumoral progression [ 2 , 10 ] . due to unspecific complaints , the diagnosis is always late , compromising the curative treatment , as in the 2 cases presented here , with advanced abdominal disease [ 7 , 9 ] . hepatic metastases are found in 42% of cases , less frequently in the lungs   and rarely in the bones or bone marrow . dsrct presents an exclusive translocation , t(11,22)(p13;q12 ) , resulting in ews and wti gene fusion [ 1 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] , which occurs mainly in the embryonic mesenchymal cells of the serosa of the abdominal organs . the primary tumor 's organ of origin could not be detected in our patients , nor did we do a genetic study since there was conclusive ih , with epithelial , mesenchymal , and some positive neuronal markers [ 1 , 2 , 7 , 8 , 9 , 15 ] . when histology is inconclusive , in up to 50% of cases , ih or genetics might help . ct is the most used imaging exam , though it might produce false - positive results . in case 1 , both ct and mri were efficient with respect to diagnosis and follow - up , but pet did not show the tumor with physiological distribution of fdg . wide tumoral resection is the prognostic factor that impacts the most on an increased survival rate , with an average of 34 months survival time . in an inoperable case our cases confirm the data : case 1 only underwent biopsy and survived 13 months ; case 2 had a larger cytoreduction and survived 34 months . a longer survival time occurs in 1530% of cases , and up to 18% will be alive in 5 years after undergoing wide surgical resection [ 9 , 13 ] . due to dsrct 's rarity , there is no standard treatment procedure . the average survival time with polychemotherapy is 32 months , with relapse being the rule . in well - selected cases , intraperitoneal the p6 protocol seems to increase the survival rate , alternating cyclophosphamide , doxorubicin , and vincristine with ifosfamide and etoposide , although it is highly myelotoxic . case 2 , treated with bevacizumab associated with chemotherapy , showed a longer partial remission ; however , he had a more extensive surgery . he underwent chemotherapy ( adriblastina and cisplatin ) with a brief partial remission and survival time of 13 months . he received chemotherapy ( paclitaxel and carboplatin ) and bevacizumab , also with partial remission , but with a survival time of 34 months . pet was not effective in restaging of the second patient , emphasizing the importance of ct or mri in dsrct . most patients have nonspecific symptoms , delaying diagnosis , and worsening the prognosis , since there are few effective treatment protocols .
here , we present 2 case reports of patients with desmoplastic small round cell tumor ( dsrct ) , a very rare and aggressive mesenchymal cancer , and we discuss 2therapeutic options for this sarcoma . 
 this report focuses on men aged 22 and 37 years , respectively . 
 the first patient presented with an abdominopelvic mass which was not suitable for surgery . 
 he underwent chemotherapy ( adriblastina and cisplatin ) with a brief partial remission and survival time of 13 months . 
 the second patient presented with an abdominal mass and underwent partial resection . 
 he received chemotherapy and bevacizumab , resulting in a partial remission and a survival time of 34 months . 
 the extent of surgery and monoclonal antibody use probably had a positive impact on survival . 
 it is necessary to include specific targeted therapies in an attempt to improve survival . 
 surprisingly , positron emission tomography was not effective in restaging of the second patient , emphasizing the importance of computed tomography or magnetic resonance in dsrct .