Circular or oval, usually more than 100 rice-grain sized or red-bean seized polyps develop diffusely throughout all parts of the colon. However among them large polyps are mixed, uniformity of the shapes and sizes of polyps is recognized at large. This is histologically adenoma, and if this is untreated this becomes cancerous, and this is inherited to posterity as an autosomal dominant trait. It revealed that this was associated with a high incidence of polyps in the small intestine/duodenum and stomach, in 1974 for the first time in Japan. Also, because small lesions were found in the bones and soft tissues more frequently in patients without large lesions in appearance if detailed scrutiny is undertaken, we could find that this was same disease as Gardner syndrome. This was proven genetically in 1991. Then, nowadays Familial Adenoma Polyposis and Gardner syndrome are comprised in adenomatous polyposis.