粘膜下腫瘍の形態を示した早期胃膠様腺癌の1例

An Early Gastric Mutinous Adenocarcinoma Exhibiting Features of a Submucosal Tumor, Report of a Case

要旨　患者は79歳，男性．タール便を主訴に受診．胃X線および内視鏡検査で，前庭部小彎に不整陥凹を伴う粘膜下腫瘍と診断された．陥凹部の生検では診断はつかなかったが，同時に発見されたS状結腸癌のためS状結腸切除術を施行した．胃粘膜下腫瘍に対してはまず腫瘍を摘出し，術中迅速病理診断で膠様腺癌と診断されたため，胃亜全摘術が施行された．病理組織学的には，胃癌細胞は粘膜下層までに限局し，正常粘膜を下から押し上げる形で増殖していた．粘膜下腫瘍様形態を示す早期胃膠様腺癌は非常にまれな疾患であり，本邦報告例は8例のみである．組織学的特徴を反映した特異的な発育形態と診断・治療について考察を加え検討した．

　A 79-year-old man was admitted to our hospital with bloody stool as his complaint. X-ray and endoscopic examinations of the stomach revealed on the antrum a typical submucosal tumor with a minute depression and an irregular margin. The biopsy specimens from the lesion showed no malignancy. The patient also had a sigmoid colon cancer, both sigmoidectomy and gastric tumor resection was carried out. Frozen section showed mutinous adenocarcinoma of the stomach, so subtotal gastrectomy with lymphatic dissection was carried out. Histopathologically, the gastric tumor was limited with in the submucosal layer and had thrust up the normal mucosa from underneath. Early gastric mutinous adenocarcinoma exhibiting features of a submucosal tumor is quite rare and only eight cases of it have been reported in Japan. Its characteristic growth pattern reflected in its histological features, clinical diagnosis and treatment are discussed in this report.