Sudden progressive abdominal pain due to large peritoneal desmoid tumor: A case report with review of literature

Desmoid tumor (musculoaponeurotic fibromatosis) is a rare locally aggressive soft tissue tumor. A subset of cases is associated with familial adenomatous polyposis (FAP), governed by the APC (adenomatous polyposis coli) gene. Typically, an intra-abdominal desmoid is a painless lump or mass with a slow progression. We report a case of 14 year old male with Asperger syndrome who presented to our hospital with acute onset of progressively worsening abdominal pain. On the physical examination a large abdominal mass was palpated in the left upper quadrant. An abdominal CT (computerized tomography) scan confirmed the mass. The tumor was resected with free tumor cell margin. The histological diagnosis was desmoid fibromatosis. The nuclear β-catenin immunohistochemistry was positive. The tumor had encroached the splenic vessels and infarcted spleen. This splenic infarction was most likely the cause of the sudden abdominal pain. The patient is alive with no postoperative symptoms or evidence of the disease 6 months after the surgery. Family history and genetic analysis of the APC gene were negative for FAP.