Ménétrier病の経過中に発生した胃底腺領域内の高分化型進行胃癌の1例

Advanced Gastric Cancer Arising in a Patient with Ménétrier's Disease, Report of a Case

要旨　患者は68歳の男性で，15年間にわたるMénétrier病の経過中に進行胃癌を発症した．入院時には既に癌性腹膜炎の状態であったため，強力な化学療法を施行したが著効は得られなかった．入院3か月後に両肺の癌性リンパ管症を併発し，死亡した．腹部に限定した剖検により腹水を伴った癌性腹膜炎が確認されたが，胃以外の腹腔内臓器原発の腫瘍は認められなかった．肉眼的には摘出胃の大彎を中心として脳回状巨大皺襞が存在し，その領域内に6.5×4.0cm大の腫瘍を認めた．組織学的には巨大皺襞の全領域にわたって腺窩上皮の過形成がみられ，粘膜固有層から粘膜下層にかけて腺管の囊胞状拡張が顕著であり，Mènètrier病に一致する所見であった．これらの巨大皺襞に囲まれて存在していた腫瘍は高分化型管状腺癌で，浸潤性増殖を示し，漿膜面に露出していた．粘膜固有層の一部には過形成性腺管から腺癌への移行を示唆する像が認められた．以上の所見から，本例はMènètrier病を基盤として胃底腺領域に発生した進行胃癌と診断された．今回の症例も含めMènètrier病と胃底腺領域癌の組織発生との関係について文献的に考察した．

　We demonstrated here advanced gastric cancer arising in a 68-year-old man with a 15 year history of Ménétrier's disease. Three months after admission, the patient died of carcinomatous peritonitis and lymphangiosis of both lungs in spite of undergoing extensive chemotherapy. An autopsy was limited to the abdominal cavity. Gross appearance of the stomach showed gyrous-shaped big folds covering most of the fundic glandular field. A firm tumor, measuring 6.5×4.0cm, was found in the area of the big folds. No primary tumor was detected in any organ such as the small intestine, large bowel, pancreas or hepatobiliary system. Histologically, most of the big folds of the stomach were composed of hyperplasia and cystic dilatation of the foveolar ducts, compatible with the Ménétrier's disease. The coexistent gastric tumor consisted of a well differentiated tubular adenocarcinoma invading the serosa and progressing to carcinomatous peritonitis. In the lamina propria, the adenocarcinoma was intimately close to the hyperplastic foveolar ducts, suggesting a transition between the both. These findings together with several case reports similar to the current study indicate that Ménétrier's disease has a potential to give rise to adenocarcinoma in the fundic gland fields of the stomach.