Rectal gastrointestinal stromal tumor: clinical features, endoscopic findings and prognosis.

Abstract Rectal gastrointestinal stromal tumor (GIST) accounts for only a small portion of all GISTs, and reports regarding its clinical features and endoscopic findings are still lacking. Thirty-two patients diagnosed as rectal GIST at Asan Medical Center, a tertiary university hospital in Korea between May 2003 and January 2011 were enrolled. The median age was 54 years (range, 31-79) with 18 males (56.2%). Common symptoms were hematochezia, anal pain, and defecation difficulty, although 11 patients were asymptomatic. The median size of tumor was 6.1 cm (range, 0.4-12.0 cm), and the median distance from the anal verge was 4 cm (range, 3 cm). The most common endoscopic finding was subepithelial tumor with normal overlying mucosa (63.1%), followed by subepithelial tumor with erosion, ulceration, or bleeding (31.6%). Preoperative imatinib was administered in eight patients (25.0%) that helped the downsizing the tumor and anal sphincter preserved. High-risk group by NIH risk classification and tumor size were associated with tumor recurrence, with the overall five-year recurrence-free survival of 67.2%. Common endoscopic feature of rectal GIST was subepithelial tumor with normal mucosa. Patients treated by definite resection with or without imatinib for rectal GIST seem to show a favorable clinical course.