Outcome of radical excision of anorectal gastrointestinal stromal tumors in Hong Kong Chinese patients.

Anorectal gastrointestinal stromal tumor (GIST) is a rare disease entity with malignant potential. Medical records of six patients (median age 68 years) with anorectal GIST who underwent surgical treatment at our institution between 1992 and 1999 were retrospectively reviewed. Four patients presented with rectal bleeding. The tumors were located in the mid and lower rectum in 4 patients and in the anal canal in 2 patients. The median tumor diameter was 4.5 cm. One patient who had undergone local excisions in another hospital presented with recurrent GIST. He refused radical excision and underwent wide local excision again. He developed recurrence 2 years later and underwent salvage pelvic exenteration, but finally died of disseminated disease. Five patients underwent initial radical excision. Among them, 3 developed recurrences (one each local, distant and both) at a median duration of 50.3 months. Two patients died of the disease, while one patient who had both local and distant recurrences resected remained alive till the end of the study period (median duration of follow-up of the 5 patients was 84.6 months). At 5 years, of 5 patients who underwent initial radical excision, 3 and 4 patients, respectively, had disease-free and overall survival. Recurrence of anorectal GIST is common despite radical excision. Nevertheless, a reasonable survival rate can be achieved.