A rare submucosal eminence of the colon.

A 38-year-old man came to our outpatient department with abdominal pain. The computed tomography (CT) scan shows no obvious abnormalities. The colonoscopy showed a submucosal eminence about 0.6cm in diameter in ascending colon, with a yellow surface color and moderate motion. Subsequently, we performed endoscopic mucosal dissection (ESD) surgery on the patient. The postoperative pathology revealed a submucosal granular cell tumor (GCT) of the ascending colon with a diameter of about 4mm. The immunohistochemistry suggestsed CD117 (-), Desmin (mucosal muscle +), S-100 (+++), CD68 (++), SOX-10 (++), Syn (+), CgA (-) , and Ki-67 (approximately 5%+).