2021 Volume 46 Issue 2 Pages 148-153
Schwannomas of the digestive tract are extremely rare, especially in the colon. We report a case of a schwannoma in the ascending colon that was successfully resected by laparoscopic surgery. A woman in her 70s underwent a colonoscopy as a follow-up for ulcerative colitis. The examination revealed a 20-mm submucosal tumor in the ascending colon. A contrast-enhanced abdominal CT study revealed a 20-mm tumor of the ascending colon without any swelling in the lymph node or distant metastasis. We performed a laparoscopic wedge resection of the ascending colon. Intraoperative rapid diagnosis suggested a schwannoma and did not reveal any signs of malignancy. The final histological findings of the resected specimen showed that spindle-shaped cells had proliferated in a palisaded/fascicular manner mainly in the muscularis propria. Immunological staining was positive for S-100 protein and negative for c-kit, CD34 and α-SMA. Based on these findings, the tumor was finally diagnosed as a benign schwannoma. Schwannoma is often difficult to diagnose pathologically prior to surgery. If a definitive preoperative diagnosis cannot be made, surgery with lymph node dissection should be performed because of the possibility of malignancy.
