A report of a case of desmoplastic small round cell tumor of peritoneum

Desmoplastic small round cell tumor (DSRCT) is a rare subtype of "small round blue cell tumors" typically arising from the peritoneum. An 18-year-old male patient presented with palpable nontender abdominal mass associated with dragging sensation. Imaging revealed a large heterogenous soft tissue mass in the pelvis and lower abdomen along with irregular peritoneal thickening. Histopathology and immunohistochemistry suggested DSRCT. Neoadjuvant chemotherapy followed by laparotomy with debulking surgery of the pelvic mass was done after 5 months of starting chemotherapy. Follow-up contrast enhanced computed tomography abdomen showed a reduction of the size of residual disease. However, follow-up magnetic resonance imaging done after 3 months of surgery showed disease recurrence. The tumor should be suspected in young males when imaging is showing a pelvic mass along with multiple peritoneal soft tissue deposits.