リンパ節転移を認めた径2mmの直腸印環細胞癌の1例

Two-mm Diameter Signet-ring Cell Carcinoma of the Rectum with Lymph Node Metastasis, Report of a Case

要旨　径2mmの直腸印環細胞癌を経験したので報告する．患者は71歳，女性で貧血の精査目的で紹介された．大腸内視鏡検査で，Raに褪色した表面隆起型病変を認め，生検を施行．大きさは2mmであったが，粘膜内には印環細胞癌の増生が認められ，粘膜下組織にもわずかに浸潤していた．リンパ節郭清のため，低位前方切除術を行った。術前に点墨を行い，切り出した直腸の生検後組織を連続切片で検索したが，腫瘍の残存は認めなかった．しかし，1群リンパ節3個に転移を認めていた．

　We happened to discover a minimal signet-ring cell carcinoma of the rectum. A 71-year-old woman was admitted to our hospital for examination of anemia. Colonoscopic examination revealed a discolored flat elevated lesion, 2 mm in diameter, in the upper rectum, and it was removed by biopsy. The histologic examination diagnosed it as a signet-ring cell carcinoma. Low anterior resection with lymph node dissection was performed. The postoperative histologic study revealed no residual carcinoma of the rectum after proctectomy. However a signet-ring cell carcinoma metastasized in three lymph nodes, 2～3 mm each, which were excised from the para-rectal region. As far as we know, no other case of minimal signet-ring cell carcinoma of the colorectum like this have been reported previously. Therfore, this case is important when considering the process of colorectal carcinoma development.