A successful operation for giant intra-abdominal desmoid tumors associated with familial adenomatous polyposis: A case report.

Desmoid tumors are benign proliferations of spindle cells originating in fibro-aponeurotic tissue. Many patients with familial adenomatous polyposis (FAP) die from desmoid tumors, which can arise spontaneously but often appear to be surgically induced by prophylactic colectomy. Desmoid tumors are the second most common cause of death in patients with FAP, second to colorectal cancer. Many patients can live a long life with desmoid tumors without symptoms, but when symptoms (ranging from bowel or ureteric obstruction to bowel perforation with abscess and fistula) appear or there is a risk of functional impairment, a wide spectrum of therapies (local and systemic) are valuable in improving the symptoms and controlling the disease. A half-Japanese, half-Caucasian male, who had been diagnosed with intra-abdominal desmoid tumors associated with FAP at age 13, was treated using abdominal wall incision for decompression and chemotherapy from the age of 38. The therapeutic outcome was progressive disease, based on the modified response evaluation criteria in solid tumors (mRECIST), and when he visited our hospital at age 41 the desmoid tumor had invaded the small bowel with a fistula to the abdominal wall. We performed a palliative operation to improve his symptoms, which were fever, abdominal pain, vomiting, and difficulty eating. As the tumor was extremely large and had invaded the small intestine, massive resection including the small intestine was required. To prepare for anticipated massive bleeding, a balloon catheter was placed in the superior mesenteric artery just prior to surgery. Although the operation was extremely difficult, following surgery the patient regained his ability to eat and when discharged was ambulatory and without short-bowel syndrome. We report our experience treating one of the largest reported intraperitoneal desmoid tumors. Resection resulted in a good postoperative course, with improved quality of life and prognosis.