壁外非連続性癌進展を伴い致死的転帰に至った早期大腸癌の1例

Early Colorectal Cancer with an Extramural Cancer Deposit Leading to Fatal Outcome, Report of a Case

要旨●患者は50歳代，女性．血便の精査で施行した下部消化管内視鏡検査でS状結腸に平坦隆起と結節から成る20mm大の病変を認めた（0-Is＋IIa型）．結節頂部の陥凹にV_I型高度不整pitを認めたためSM深部浸潤癌と診断し，腹腔鏡下S状結腸切除術を施行した．病理組織学的には結節部に粘膜下層まで浸潤する高分化腺癌（SM2 4,700μm）を認めた．平坦隆起部は腺底部に増殖帯を認め表層は分化するsuperficially serrated adenomaであった．漿膜下層に壁外非連続性癌進展とリンパ節転移を認めた．術後補助化学療法後を施行するも，術後11か月目に転移再発し，術後15か月目に原病死した．

　50's-year-old female presented with hematochezia. Total colonoscopy revealed a superficial, elevated lesion with a large nodule（size, 25mm）in the sigmoid colon（0-Is＋IIa）. The upper portion of the nodule demonstrated type-VI invasive pattern pits. Laparoscopic sigmoidectomy was performed for T1b cancer. Histologically, tubular adenocarcinoma invaded into the deep submucosal layer（SM2, 4,700μm）. The flat, elevated lesion revealed a superficially serrated adenoma. A extramural cancer deposit without any lymph node structures was detected. The patient was treated with adjuvant chemotherapy ; however, she relapsed and died of tumor progression 15 months postoperatively.