特異な組織反応を伴ったびまん浸潤型大腸癌の1例

Diffusely Infiltrating Colon Carcinoma with Unusual Tissue Reaction, Report of a Case

要旨　患者は41歳，男性．主訴は便柱狭小化と排便回数増加．注腸検査では，直腸上部からS状結腸にかけて12cmの鉛管状狭窄を認め，CT検査では，腸管壁の全周性肥厚と周囲への浸潤像を認めた．内視鏡検査および血管造影では炎症性疾患が示唆される所見であった．摘出標本の肉眼所見では狭窄部は巨大皺襞様に不整に隆起し，中央部に隆起性腫瘤がみられ，組織学的には高分化腺癌より成る腫瘍と炎症巣が粘膜下層を中心に広範にあり，またCrohn病様病変がみられた．病理組織学的検討の結果，高分化腺癌に炎症性細胞浸潤を伴ったことより，Crohn病様病変を生じたびまん浸潤型大腸癌であり，高分化腺癌のびまん浸潤型の発育形式などに多くの示唆が得られた．

　A 41-year-old man complaining of pencil-shaped stool and an increased number of bowel movements was shown by barium enema to have a lead-pipe-like stenosis, 12 cm in length, in the upper rectum to the lower sigmoid. CT scan of that area showed thickened colonic wall involving the whole circumference and infiltrated surrounding tissue. Endoscopic and angiographic studies suggested an inflammatory process. Gross observation of the surgically resected specimen revealed the stenosis resulting from irregular giant folds with an elevated mass in the centre. Histological study showed a well differentiated adenocarcinoma surrounded by inflammatory nests spreading extensively in the submucosal layer. These inflammatory changes looked like Crohn's disease.

　Based on these histopathological finding's, i.e., a well differentiated adenocarcinoma with inflammatory cell infiltration, we considered this patient as having had diffusely infiltrating colon carcinoma producing Crohn's disease-like reaction. It is likely that this case sheds some light on the development of diffusely infiltrating well differentiated adenocarcinoma.