Extrapelvic Uterus-like Masses Presenting as Colonic Submucosal Tumor: A Case Study and Review of Literature.

A uterus-like mass (ULM) is a central cavity lined by endometrial glands and stroma and surrounded by thick-walled smooth muscles. To date, 31 cases of ULM have been reported in the English literature. ULM typically presents as a single mass and is located in the pelvic cavity. We report here a very rare case of multiple extrapelvic ULMs involving the cecum, descending colon, and mesocolon. After extensive literature research, our case appears to be the first case of multiple ULMs found in extrapelvic sites and the first case of ULM in the colon. The present case suggests that ULM should be included in the differential diagnosis of colonic submucosal tumors in female patients with chronic abdominal pain or menstruation-associated symptoms.