消化管顆粒細胞腫の診断と治療

Clinical and Pathologic Features of Granular Cell Tumors of the Gastrointestinal Tract

要旨　当科における25例26病変の消化管顆粒細胞腫（granular cell tumor；GCT）に文献的考察を加え，その臨床像と病理学的特徴について検討した．男女比は19：6で，平均年齢は50.9歳（29～73歳）であった．腫瘍径は10mm前後が多く，20mm以上のものは認めなかった．臓器別では16例（64％）と食道に多く，1例が2病変の多発例で，次いで大腸7例（28％），胃は2例（8％）のみであった．好発部位は中下部食道，胃体部，右側結腸であった．内視鏡上は黄色調の粘膜下腫瘍（submucosal tumor；SMT）で，いわゆる大臼歯状のものは10mm以上の食道GCTにみられ，10mm以下のものは縦長の台状もしくは半球状のものであった．5mm以下の大腸GCTは丈の低いIIa様のSMTで，5mm以上では半球状を呈し2例で基部にくびれを有していた．表面に陥凹や潰瘍は認めなかった．生検診断率は87.5％と良好であったが，大腸GCTでは57.1％とやや低率であった．内視鏡的に切除された14病変中13病変（92.9％）は病理学的に完全切除であった．切除標本で2例に軽度の核の多形性，1例に核分裂像が認められたが全例良性と判定された．

　We analyzed the clinical and pathologic features of 25 patients with granular cell tumors (GCTs) of the gastrointestinal tract and reviewed the literature. Patients ranged in age from 29 to 73 years (average 50 years) and the male/female ratio was 19/6. The esophagus was the most common anastomotic site, involved in 16 cases (64％). The large bowel was involved in 7 cases (28％) and the stomach was involved in only 2 cases (8％). One case of GCT showed two multiple tumors synchronously in the middle esophagus. The average tumor size was 8mm (range 2～15mm). All the esophageal GCTs arose in the middle or distal esophagus, and 6 of the 7 large bowel GCTs (85.7％) were located in the cecum or right-side colon. Endoscopically, most of GCTs showed a yellowish submucosal nodule, and GCT of the esophagus measuring more than 10mm revealed the characteristic first molar-like appearance, but those measuring less than 10mm showed non-specific hemispherical or plateau-like features. GCT of the large bowel measuring less than 5mm showed slightly elevated yellowish submucosal tumors, while those measuring more than 5mm revealed hemispherical appearance. Neither central depression nor ulceration was recognized on the surface. Both of the two GCTs of the stomach arose in the gastric body. Twenty-one of the 24 lesions (87.5％) were diagnosed as GCT by endoscopic biopsy, but, in the large bowel, only 4 of the 7 (57.1％) cases were diagnosed as GCT. Fourteen lesions were treated with endoscopic resection (EMR-C :8, Strip biopsy :2, ESD :1), and 13 lesions (92.9％) were resected completely. In the resected specimens, two cases showed focal pleomorphism and a mitotic feature, but, histologically, all the cases were diagnosed as benign GCT.

　1) Department of Pathology, Fukuoka University Chikushi Hospital, Chikushino, Japan