Female patient, 69y. Anemia and positive family history for colon carcinoma. Colonoscopy: Small round polyp within the lumen of the transverse colon. Histology: Tumor of smooth muscle fibers arising from the muscularis propria with normal

mucosa overlying (Leiomyoma).

Leiomyomas of the colon: Smooth muscle tumors, which include benign leiomyomas and malignant leiomyosarcomas, are the most common, nonepithelial tumors of the gastrointestinal tract. The colon and rectum are rare sites for leiomyomas, representing 3 % of all gastrointestinal leiomyomas. The commonest location in the large bowel is the descending and sigmoid colon. Leiomyomas can present with a variety of symptoms including abdominal pain, constipation,

weight loss, and bleeding

The tumors arise from the muscularis mucosa or propria, or vascular smooth muscle. On colonoscopy leiomyomas are intramural or pedunculated lesions that can be similar in appearance to adenomatous polyps.

Treatment includes complete removal, recurrences are extremely rare.

1) Kemp CD, Arnold CA, Torbenson MS, An unusual polyp: a pedunculated leiomyoma of the sigmoid colon. Endoscopy. 2011;43 Suppl 2 UCTN:E306-7. Epub 2011 Sep 13

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