Colonic invagination due to transverse colon cancer accompanied with an inflammatory myofibroblastic tumor of the major omentum

Abstract

A 48-year-old woman with increasing abdominal pain revisited our outpatient clinic, although gastric endoscopy performed the day before had revealed no abnormalities. An enhanced CT revealed invagination in the left side of colon. Intraoperative findings during emergency surgery revealed that the tip of invagination existed in the sigmoid colon, which was easily restored to its normal position by hand manipulation. We found a tumor in the transverse colon as the tip of invagination and another 1cm nodule in the major omentum at 15cm in an anal direction from the previous tumor. Transverse colectomy removing the omental tumor, and colostomy were performed. Pathological findings revealed a poorly differentiated adenocarcinoma in the colon and an inflammatory myofibroblastic tumor (IMT) in the major omentum. The patient received surgery for ileus and stoma closure because of adhesive ileus 31 days after the first surgery. There was no obvious lesion identifiable as the origin of IMT during the second surgery or by the findings of positron emission tomography-CT after surgery. We speculated that the origin of the IMT might be the major omentum. No report of invagination due to colon cancer accompanied with IMT was found. Although IMT usually is a low-grade malignancy with a good prognosis, recurrence should be considered, including colon cancer in such cases. © 2012 The Japanese Society of Gastroenterological Surgery.