Leiomyosarcoma of the rectum. Report of two cases illustrating an unusual presentation and the need for repeated biopsy.

Two cases of leiomyosarcoma of the rectum are reported in which the diagnosis required repeated biopsy in order to differentiate the lesions from their benign counterparts and other tumors. One patient presented with an ischiorectal abscess. The author is unaware of any similar presentation reported previously. Close follow-up is essential in order to detect local recurrence. There is no evidence of any significant advantage in the use of chemotherapy or deep x-ray therapy, and they were therefore not used in either case.