胃のgranular cell tumorの1例

Granular Cell Tumor of the Stomach, Report of a Case

　granular cell tumor（以下GCT）は1926年のAbrikossoff'の報告以来，今日まで多数の報告がみられる．それらの多くは皮膚，舌，口腔内，気管，気管支，乳腺などであるが，全身の臓器に広く発生している．しかし，消化管のうち胃に発生したものは極めて少なく，欧米ではAbdelwahabが1983年に18例を集計しており，本邦ではTable 1に示すように自験例を含めて7例にすぎない．筆者らは胃に発生したGCTの1例を経験したので文献的考察を加えて報告する．

　The patient, a 46-year-old woman complaining of epigastric dull pain, was diagnosed to have a gastric polyp four years ago.

　She has been almost asymptomatic up to date. Recently, she visited our clinic for examination of the gastric polyp. Radiologic and endoscopic examinations of the gastrointestinal tract revealed a polypoid lesion at the posterior wall and the middle body of the stomach. The lesion showed a depression at the top of the tumor and a bridging fold. The findings were considered as a submucosal tumor. We recommended her for operation because gastric carcinoid was suspected. Radical distal gastrectomy was performed and the resected specimen showed a polypoid lesion, 13×10 mm in diameter, 7 mm in height. Perpendicular section of the tumor was yellowish-white and clearly lined submucosal mass. Microscopically small nuclei and granular cytoplasms were observed in the tumor nest. Granules stained with PAS reagent, not digested for amylase, were seen in the cytoplasm. Electron micrograph of tumor cells showed membrane-delimited granules in the cytoplasm. Tumor cells exhibited a positive reaction with CEA immunohistochemical reaction by the PAP and with S-100 protein immunostaining. These findings lend substantial support to the opinion that the granular cell tumor is of Schwann cell origin.