PG型でsm2浸潤を呈した直腸癌の1例

Type Is Polypoid-growth Carcinoma of the Rectum with Submucosal Invasion, Report of a Case

要旨　患者は48歳，女性．右下腹部痛を主訴に近医を受診．大腸内視鏡検査が施行され，直腸に隆起性病変を認め，精査・加療目的に当院紹介となる．注腸X腺検査，下部消化管内視鏡検査にて，Rsに大きさ約15mmのIs型病変を認めた．隆起の起始部は腫瘍粘膜で構成されていることからPG typeと判定した．病変の表面は分葉構造を呈し，表面粗であった．同部位に輪郭不明瞭なVI型pit patternを認めた．深達度sm massiveと診断し高位前方切除術施行．組織学的に腺腫を合併する細胞異型度の高い高分化型腺癌深達度sm2，ly0，v0，n1であり，腫瘍先進部において簇出像が認められた．

　A 48-year-old woman visited a local doctor with right lower abdominal pain as her chief complaint and was referred to our hospital for the treatment of rectal tumor. Double contrast barium study and endoscopy revealed a type Is tumor measuring about 15 mm in the rectum. The tumor was covered with neoplastic mucosa, which was suggestive of PG-type carcinoma. Its surface showed a lobular structure and roughness. At the top of the lesion was type VI pit pattern with unclear outline, which led to the diagnosis of an sm massive cancer. High anterior resection was performed.

　Histologically, the lesion proved to be a well-differentiated adenocarcinoma with adenomatous components, invading the submucosal layer. Budding was found in the submucosal invasion front.

　1) Department of Internal Medicine, Kushiro City General Hospital, Kushiro, Japan

　2) Department of Surgery, Kushiro City General Hospital, Kushiro, Japan

　3) Department of Pathology, Kushiro City General Hospital, Kushiro, Japan

　4) First Department of Internal Medicine, Sapporo Medical University, Sapporo, Japan