Experience of surgical treatment in a granular cell tumor in the qscending colon: a case report

We report a case about successful surgical treatment of a granular cell tumor in the ascending colon. A 36-year-old man underwent screening colonoscopy. An endoscopic examination revealed a 10-mm yellowish and hemispheric mass in the ascending colon, and lower endoscopic ultrasonography revealed a hypoechoic-to-isoechoic mass invaded the submucosal layer. The mass was suspected to be a colonic carcinoid tumor. Based on the preoperative evaluation, endoscopic complete resection was considered difficult. Therefore, the lesion was removed via laparoscopic right hemicolectomy. Histological examination revealed that the tumor consisted of nests of polygonal cells with abundant granular eosinophilic cytoplasm. Immunohistochemical staining revealed diffuse positivity for S100 and CD68. Therefore, the tumor was diagnosed as a granular cell tumor. We suggest that surgical resection should be considered if it is located in the thin-walled ascending colon prone to perforation, difficult to rule out malignant tumor due to submucosal invasion, or to remove endoscopically.