ⅡC型早期大腸癌が認められた家族性大腸ポリポージスの1例

A Case of Early Colonic Cancer Type Ⅱc Associated with Familial Polyposis Coli

　大腸癌が腺腫に由来するか，あるいは，いわゆるde novoに発生するかは，興味のある問題として，従来それぞれの立場から，多くの研究，主張があるところである．大腸癌が腺腫に由来すること，すなわち大腸腺腫の癌化の可能性は，一般に広く認められていると考えられる．事実，近年本邦においても多く報告されるようになった，いわゆる大腸早期癌のほとんどは隆起型であり，まだ典型的な陥凹型早期大腸癌の報告をみていないといえる．

　最近われわれは，家族性大腸ポリポージスという隆起性病変を主体とする疾患において，典型的な微小なⅡc型早期大腸癌を認めた，きわめて興味のある症例を経験した．この症例にっいて，診断的立場から報告する．

　Types of early colonic cancer have been almost protruded ones, and a typical early colonic cancer of depressed type has rarely been reported.

　The present case showed typical Ⅱc type early colonic cancer with familial polyposis coli.

　The patient : a 37-year-old man with a chief complaint of anal bleeding. His two sisters have been operated on with a diagnosis of familial polyposis coli.

　Radiological and endoscopic studies of the colon and the resected specimen showed a typical Ⅱc type lesion, which was minute and irregular-shaped, measuring 0.8×0.5 cm, with convergence of the folds on the distal portion of the transverse colon.

　Histological fingings showed well-differentiated adenocarcinoma limited within the mucosa, or a Ⅱc lesion with highly cellular atypism. Throughout the entire colon and rectum, there were numerous polypous nodules varing in size from a rice-grain to a thumb-tip, which were histologically adenomatous polyps and of no malignancy.

　Diagnosis of this case depended on the double contrast radiogram of colon. It is a very interesting case when we think of malignant change of familial polyposis coli and origination of colonic cancer.