Rectal leiomyosarcoma: a rare and long-term complication of radiation therapy.

Leiomyosarcoma of the rectum can develop as a late complication in patients with a history of pelvic irradiation. We report the case of a patient who developed rectal leiomyosarcoma 13 years after receiving radiation for treatment of a stage 2 squamous cell cancer of the anus. This was detected on physical examination.