Abstract
Neurilemoma arises from Schwann cells and it is rare to see it in the digestive tracts, especially in colon. The case was a 80-year-old male who had a barium enema study and a tumor of 20mm in size was discovered in his colon. Colonoscopy revealed a submucosal tumor and the biopsy specimen of the deep layer of colonic tissue taken after resecting the tip of the mucosa by EMR did not reveal definite pathological diagnosis. Sigmoid resection was carried out by laparoscopic method with suspected diagnosis of GIST. The resected tumor was encapsulated, extending from immediately below lamina muscularis mucosae to subserosal layer penetrating through the mucosal layer with spindle cells arranged in fascicular fashion. Immunological staining revealed c-kit (-), S-100 (+), and GFAP (+) and the diagnosis of neurilemoma of sigmoid colon was made. In case histological diagnosis could not be obtained, it may be necessary to perform diagnostic resection considering the possibility of a malignant tumor such as GIST.