Ⅱa＋Ⅱc様形態を呈した大腸腺腫内癌の1例

Ⅱa+Ⅱc-like Tubular Adenoma Including Minute Cancer, Report of a Case

要旨　59，歳男性，腹部膨満感を主訴として受診．注腸検査，大腸内視鏡検査で右結腸曲に中心陥凹のある無茎性隆起を指摘されたが，生検ではGroup 3であった．腺腫内癌の可能性も考慮し，結腸部分切除術が行われた．切除標本では15×12×2mmの環状隆起であり，病理検索で陥凹部から隆起部にかけ，一部に粘膜内に限局した高分化腺癌が認められたが，主として中等度～高度の異型を示す腺管腺腫と診断された．最近，中心陥凹が必ずしも悪性の決め手とは言えず，中心陥凹のある扁平隆起で良性病変がまれならず存在することが明らかとなりつつあり，若干の文献的考察を加え報告した．

　A 59 year-old man complained of a sensation of abdominal fullness since three months ago. He visited our hospital for further examination.

　Laboratory examination showed no abnormalities, Barium enema and colonoscopy showed a sessile protruded lesion with central depression in the hepatic fiexure of the colon. Biopsy specimens revealed a tubular adenoma with moderate atypia. Partial colectomy was performed because of suspicion of focal cancer.

　Resected specimen showed a sessile protruded lesion with central depression, 15×12×2mm in size. Histologically it was a tubular adenoma including minute cancer limited to the mucosa.

　Recently it is shown that an elevated lesion with central depression is not only the case of cancer but also that of benign tumor.