胃癌術後11年目に発症した続発性linitis plastica型横行結腸癌の1例

Secondary Linitis Plastica Type Transverse Colon Carcinoma Discovered 11 years After Total Gastrectomy for Gastric Carcinoma, Report of a Case

要旨　11年前に胃癌に対して胃全摘術を行った75歳の男性が，大腸内視鏡検査で横行結腸の全周性狭窄を指摘された．生検では低分化腺癌と診断した．注腸造影検査にて横行結腸の脾彎曲部寄りに境界不明瞭な全周性狭窄と収束像を認めた．手術時，横行結腸癌は，腹壁および肝の一部へ浸潤していたため，合併切除を行った．また，小腸間膜に白色調の小結節を認め，術中迅速病理診断で胃癌の腹膜播種と診断した．横行結腸切除標本の組織学的所見は，低分化腺癌が粘膜表面から漿膜までdiffuseに浸潤し，linitis plastica型（硬癌）と診断した．粘液染色では粘膜固有層を中心にPAS陽性の印環細胞癌が混在しており，胃癌と同様の所見であった．

　We were noticed during a periodic colonoscopic examination that circumferential stenosis of the transverse colon had appeared in a 75-year-old male patient, who underwent total gastrectomy for advanced gastric carcinoma 11 years ago. Pathologic examination of the biopsy specimen revealed the invasion of poorly differentiated adenocarcinoma into the submucosa. Barium enema examination demonstrated ill-defined circumferential stenosis and fixed transverse parallel folds at the distal transverse colon. We performed a resection of the transverse colon and a part of the liver and abdominal wall involved by the cancer. Through pathological examination of the frozen section, we diagnosed small nodules on the intestinal mesentery as peritoneal dissemination of gastric carcinoma. On pathological investigation of the transverse colon, poorly differentiated adenocarcinoma invading from the mucosa through the serosal surface was observed. It showed the configuration of so-called linitis plastica type carcinoma. The mucous staining of the mucosal layer of the carcinoma in the transverse colon was the same as that found in gastric carcinoma. It was mainly composed of signet-ring cell carcinoma with PAS positive mucous.