Rectal granular-cell tumor difficult to distinguish from carcinoid tumor.

A 60-year-old man had a positive fecal occult-blood test on a medical check-up. Colonoscopy revealed a yellowish-white submucosal tumor 8 mm in diameter in the rectum. Endoscopic ultrasonography showed a well-demarcated mass with a homogeneous, low-level, internal echo in the second to third layers of the rectal wall.