粘膜下腫瘍様形態を呈した胃型の分化型胃癌（進行1型＋Ⅱa型）の1例

Differentiated Adenocarcinoma of the Stomach (Advanced Type Ⅰ and Ⅱa) Mimicking a Submucosal Tumor, Report of a Case

要旨　粘膜下腫瘍様の形態を呈した胃型の分化型胃癌（進行癌1型＋Ⅱa型）の1例を経験した．患者は71歳の男性．3年前の胃X線検査で胃体上部後壁に大きさ約2cmの隆起性病変が発見されたが，内視鏡的生検診断はGroupⅠであったことから，胃粘膜下腫瘍の診断のもとに経過観察が行われた．3年間の経過観察中，計3回の内視鏡的生検が行われ，前2回の生検はいずれもGroupⅠの診断であった．その後，病変は大きさ約8cmの腫瘤へ急速に増大し，3回目の内視鏡的生検でGroupⅤ（tub1）と診断され，手術切除が行われた．病理診断は，肉眼型1型＋Ⅱa型，大きさ85×75mm，組織型tub1（胃型分化型腺癌），se，ly（＋），v（－），INFβ，StageⅡで，病変は胃底腺領域に存在していた．X線・内視鏡ならびに生検組織診断にとって，示唆に富む症例と思われたので報告した．

　We report a case of differentiated adenocarcinoma of the stomach (advanced type Ⅰ and Ⅱa) mimicking a submucosal tumor. A 71-year-old man underwent upper gastrointestinal radiologic examination three years before, which detected an about 2 cm sized protruding tumor at the posterior wall of the upper body. Subsequent endoscopic biopsy examination showed group Ⅰ. During the follow-up period of three years, three endoscopic biopsies were performed and first two biopsy specimen were diagnosed as group Ⅰ, but the lesion grew rapidly about 8 cm in size and the third biopsy specimen revealed group Ⅴ (tub1). He underwent surgical resection. Pathologic diagnosis was macroscopically type Ⅰ ＋ Ⅱa, 75 mm × 85 mm in size on the fundic gland area, and microscopically tub1 (differentiated adenocarcinoma of the stomach type), se, ly (＋), v (－), INFβ, Stage Ⅱ. This case is, we believe, informative to the radiologic, endoscopic and biopsy diagnosis.