A Case of Schwannoma in the Ascending Colon

• Published in: Nippon Daicho Komonbyo Gakkai Zasshi Vol. 72; no. 8; pp. 503 - 508
• Main Authors: Misao, Yuki, Ichikawa, Kengo, Tawada, Masahiro, Kume, Makoto
• Format: Journal Article
• Language: English; Japanese
• Published: The Japan Society of Coloproctology 2019
• Subjects: colorectal; schwannoma; submucosal tumor
• ISSN: 0047-1801; 1882-9619
• DOI: 10.3862/jcoloproctology.72.503

We present a case of schwannoma that occurred in the ascending colon. The case was a 59-year-old female. An elevated lesion of about 5 cm in size was found in the ascending colon as a result of a complete physical examination. Colonoscopy showed a submucosal tumor and so a boring biopsy was performed, but a final diagnosis could not be made. We performed laparoscopic ileocecal resection (with D2 lymph node dissection), based on a preoperative diagnosis of submucosal tumors including GIST. Histological findings of the resected specimen showed that spindle-shaped tumor cells had proliferated in palisaded/fascicular forms mainly in the muscularis propria. Immunological staining was positive for S-100 protein, and negative for c-kit and α-SMA. From these findings the tumor was diagnosed as benign schwannoma. Most schwannomas of the colon are regarded as benign, and lymph node dissection is not necessary if a definitive diagnosis of benignancy is established preoperatively. Therefore, submucosal biopsies should be performed whenever possible. However, if a preoperative definitive diagnosis is not established, choosing an operative procedure with lymph node dissection should be appropriate in consideration of the possibility of malignancy.