Gastrointestinal stromal tumors of the rectum: report of five cases.

We report on five patients (three males and two females), with a median age of 66.2 years (range, 58-73 years) who were admitted in our department from April 1998 until January 2004 with the diagnosis of rectal gastrointestinal stromal tumor (GIST). Their main symptoms were rectal bleeding, constipation and abdominal discomfort. Two patients were treated by an abdominoperineal resection of the rectum. One patient received palliative surgical treatment and adjuvant therapy with imatinib for metastatic disease. Another patient presented with complete rectal prolapse, and was treated with Delorme's procedure. The subsequent pathological examination of the resected specimen showed positive resection margins and was given adjuvant therapy with imatinib. Finally, one case was considered inoperable. However, after nine months of treatment with imatinib, the magnetic resonance imaging (MRI) scan revealed a significant reduction in the tumor size, and the patient was treated with abdominoperineal excision of the rectum. All cases have been proved to be immunohistochemically positive for the CD117 and the CD34 stain. During the follow-up period (mean duration 3.7 years), one patient died of progressive disease while the other four had no sign of recurrence.