A family with atypical colonic polyposis and gastric cancer: a three-decade followup.

A three-decade followup of a family in whom multiple colonic polyps were found in 5 out of 11 members of one generation is presented. In 3 of these members, cancer was present in the colorectum. The clinical picture as well as the pathologic findings differ from those seen in familial polyposis. In the previous generation two cases of gastric cancer were found, as well as one case of colonic cancer. The high incidence of colonic polyps and cancer suggests a hereditary disease, but the mode of transmission cannot be definitely determined without following this family for a longer period.