A case of intra abdominal desmoid tumor preoperatively diagnosed as a pancreatic tumor

We report a case of intra abdominal desmoid tumor that was preoperatively diagnosed as pancreatic tumor. The patient was a 23-year-old woman who was diagnosed as having a pancreatic tumor at the time of abdominal ultrasound, which revealed acute intestinal inflammation. Abdominal CT visualized a well-defined, ovoid tumor in the pancreatic body, which showed slight contrast enhancement. No invasion into the surrounding organs was noted. Multiple imaging studies failed to provide a definitive diagnosis and we performed a laparotomy. The tumor was located anterior to the pancreatic body, invading the vessels on the lesser curvature side and the stomach wall. Since these findings suggested a malignant tumor, we resected the pancreatic body and tail with splenectomy. The postoperative histopathological diagnosis was desmoid tumor. This patient underwent surgery under a diagnosis of pancreatic tumor; however, the tumor grew, apparently protruding from the pancreas, was well-defined, and had a diameter of about 3cm, with no influence on the pancreatic duct system. In such a case, an extrapancreatic lesion should be considered, and the differential diagnosis should include desmoid tumor, although it is rare.