Multiple Granular Cell Tumors of the Colon-Report of a Case

Abstract

Multiple granular cell tumors (GCTs) of the intestine are reportedly very rare. In this report, we present the case of a 55-year-old male patient with multiple GCTs of the right colon. Colonoscopy revealed four submucosal tumors (SMTs) measuring 15 mm in diameter. The tumors were yellowish-white. Three SMTs were removed by endoscopic polypectomy, and the remaining SMT by laparoscopy assisted colectomy. All lesions were well demarcated and limited to the submucosa. A pathological examination revealed that the resected margins of all the lesions were free of tumor cells vertically and horizontally. The tumors had eosinophilic granules in the cytoplasm, which showed a positive PAS reaction. Immunohistochemically, the tumors were strongly positive for the S-100 protein and NSE. On the basis of these findings, all the four tumors were identified as GCTs. This is the sixth case report of multiple GCTs of the colon in Japan. The differential diagnosis between GCTs and other SMTs is often difficult. A complete local resection is required for the accurate diagnosis of GCTs.