[A Case of Giant Abdominal Desmoid Tumor in a Young Man].

Desmoid tumor is a rare tumor of the soft tissue. The frequency of occurrence is 2.4 to 4.3 cases per year per million people, which is a very rare disease. We experienced a huge intra-abdominal desmoid tumor which is thought to be the primary mesentery. The case was a male in his 20s. He visited a nearby doctor with a complaint of abdominal bloating and abdominal pain. Abdominal contrast CT revealed a huge abdominal mass with a clear boundary of 35×25 cm in size extending from the upper right abdomen to the pelvis. Surgery was performed with a diagnosis of an intra-abdominal mass. Open abdominal tumor resection. Due to infiltration into the duodenum, transverse colon, and pancreas, right hemicolectomy and duodenal combined resection were performed. The pathological diagnosis was a diagnosis of desmoid tumor.