大腸顆粒細胞腫の1例

Granular Cell Tumor of the Colon, Report of a Case

要旨　S状結腸に発生した顆粒細胞腫の1例を経験した．患者は交代性の便通異常を主訴に来院した71歳の女性で，注腸X線検査および内視鏡検査でS状結腸に約8mm大の広基性の腫瘤を認めた．腫瘤は中心が膨隆し，乳房様に2段となった特異な形態を呈していた．超音波内視鏡検査では第3層に均一な低エコーを認め，カルチノイドや粘膜筋板由来の筋腫との鑑別が困難であったが，ポリペクトミー可能と判断された．ポリペクトミーで摘出された腫瘍の大きさは8×8mmであった．病理診断は，H・E染色では細胞質に好酸球性の顆粒を有する細胞から構成され，免疫組織染色でS-100蛋白陽性の顆粒細胞腫であった．

　A case with granular cell tumor of the sigmoid colon was reported. A 71-year-old female patient visited our hospital complaining of bowel movement disturbance. Barium enama x-ray and colonoscopy dsclosed a broad-based tumor sized 8 mm in diameter in the sigmoid colon. The tumor was protruded in the center, presenting a breast-like appearance. Endoscopic ultrasonography revealed a uniformly low-echoic mass in the third layer; however, the differentiation with carcinoid or leiomyoma was considered difficult. Endoscopic polypectomy was performed; the retrieved tumor was 8×8 mm in dimensions. Histology with H・E staining revealed the presence of eosinophilic granules in the cytoplasm of the tumor cells, and immunohistochemistry for S-100 protein was positive. So the diagnosis of granular cell tumor was made.