Colonic cancer arising in polyposis coli.

Polyposis coli is a well-known inheritable disease due to the action of a single autosomal dominant gene. The affected patient has in his colon innum- erable small polypoid excrescences from the mucosa and, given sufficient time, one or more of these develops into a malignant epithelial tumour, carci- noma of the colon. Carcinoma of the colon also, indeed much more frequently, occurs in patients who do not have multiple colonic polyps; in such