Two Cases of Leiomyoma in the Colon Masquerading as Other Types of Colonic Pedunculated Polyps

Abstract

We describe two cases of leiomyoma in the colon that were diagnosed histologically after endoscopic resection. The first case was a 79-year-old Japanese woman who presented with a pedunculated polyp of 14 mm length at the splenic flexure. Preoperative diagnosis suggested a colonic mucosubmucosal elongated polyp. The second case was a 29-year-old Japanese woman who presented with a pedunculated polyp of 40 mm length at the hepatic flexure and had an ulcer on top of the polyp. Preoperative diagnosis suggested an inflammatory fibroid polyp. A pathological diagnosis of colonic leiomyoma was made after endoscopic resection in both cases. Both tumors were confirmed to originate, not from the proper muscle layer, but from the muscularis mucosae. These cases underscore that although colonic involvement is infrequent, leiomyomas can display pedunculated morphology in the colon rather than the typical gross appearance of gastrointestinal submucosal tumors seen with sessile morphology.

Leiomyoma in the Transverse Colon With Resection

“…Choi et al reported that only about 46% of colorectal leiomyomas were diagnosed accurately based on their endoscopic features [ 6 ]. Ikeda et al speculated this could be due to the scarcity of leiomyomas occurring as pedunculated lesions; thus, physicians are less likely to identify them morphologically [ 11 ]. However, the rate of accurate diagnosis of colorectal leiomyoma has been increasing with the increased frequency of screening colonoscopies [ 6 ].…”

Colonic Mucosubmucosal Elongated Polyp in the Sigmoid Colon on Surveillance Colonoscopy

“…9 Unlike the more common esophageal leiomyomas arising from the muscular layer and thus presenting as subepithelial tumors, colonic leiomyomas arise from the muscularis mucosae and infrequently can present as semipedunculated or pedunculated lesions. 10 An inverted diverticulum often occurs in the background of diverticular disease and histologically appears either normal or with mild chronic inflammation in mucosa and submucosa. Endoscopic resection may result in perforation.…”

Colon Leiomyoma Diagnosed and Treated with Endoscopy

“…Large lesions can cause abdominal pain, intestinal obstruction, rectal bleeding, and perforation [2,4,7]. Surgery is the treatment of choice for large leiomyomas [9,10]. Small leiomyomas can appear as conventional polyps, which may alter the method used for removal.…”