LEIOMYOSARCOMA OF THE RECTUM AND ANAL-CANAL

Leiomyosarcoma of the rectum and anal canal is rare and the optimal tr eatment is not clear. Eight patients with isolated anorectal leiomyosa rcoma treated surgically were reviewed. The age ranged from 44 to 76 y ears (median 63 years) and the follow up ranged from 6 months to 4.5 y ears (median 2 years). All patients were symptomatic at presentation. All tumours involved the muscularis propria of the low and/or mid-rect um with three tumours also involving the anal sphincters. The tumour s ize ranged from 1.2 to 10 cm (median 4 cm). Mucosat involvement occurr ed in only three patients and there was no lymph node involvement. All showed microscopic infiltration at the advancing border, despite macr oscopic circumscription. Only one patient was thought to have a tumour sufficiently small (3 cm) and localized on clinical and intrarectal u ltrasound examinations (UST2N0) to be suitable for wide local excision . That patient remained tumour-free after 2 years. The remaining patie nts (88%) were treated by abdominoperineal resection. The disease free interval in this latter group ranged from 3 months to 4.5 years. All recurrences were detected within 15 months of surgery and the mean int erval from detection of recurrence to death was 9 months. Using a hist ological grading system that included tumour differentiation, mitotic count and amount of necrosis, high grade sarcomas were associated with a worse prognosis. Other factors associated with a poor outcome inclu ded large tumour size (> 6-7 cm) and prior incomplete local excision.