Ⅱc型早期胃腺類癌の1例ならびに文献的考察

A Case Report of Early Gastric Adenoacanthoma and Brief Review of its Literature

　胃に原発する扁平上皮癌（類表皮癌）ないし扁平上皮癌と腺癌の混在する腺類癌（類腺癌，腺棘皮細胞癌）は，比較的稀な疾患とされており，これまでに諸外国の症例を含めて115例報告されている．いずれの症例もその診断は手術または剖検により発見された進行癌であるが，今回私どもは胃内視鏡検査でⅡc型早期胃癌と診断し，生検所見ではAdenocarcinoma tubulareで明らかな扁平上皮様分化形態を示さなかったが，術後の胃組織学的検索の結果，腺類癌と診断した1症例を経験したので報告する．

　A 44-year old-man visited our out-patient clinic with a chief complaint of occasional epigastralgia after taking alcoholic drink. Gastrointestinal series revealed poor destensibility over the entire circumference of the stomach wall, irregularity and rigidity of contour in the antrum, associated with irregular mucosal folds.

　The patient was diagnosed as early gastric cancer of superficial flat type after endoscopic examination which disclosed over the entire circumference of the pyloric mucosa irregular shallow depressions with greyish white coat and uneven basis containing bleeding spots. Operation revealed a lesion, masuring 6.7 by 3.3 cm, spread along the pyloric girth. Histological diagnosis was adenoacanthoma with invasion localized in the submucosa and squamous cell carcinoma metastasis in a subpyloric lymph node. It is reported that there have been 47 cases of adenoacanthoma in Europe and America, and 13 cases in our country, 60 cases altogether, 40 males and 15 females.

　Reported locations of the tumor are the pylorus in 38 cases (71.7%), the body in 8 cases (15.1%), and the cardia in 4 cases (7.5%), indicating the highest incidence in the pylorus. Age distribution of this disease ranges from 29 to 88 years with the highest occurrence in the age group 50～59 and another considerably high occurrence in the age group 30～39.

　All the cases of this disease hither to reported are of advanced gastric cancer, and we report here a patient diagnosed as early gastric cancer of Ⅱc type exhibiting adenoacanthoma.