In the nomenclature of intestinal tumors, the term "polyp" is useful in describing what is seen with the unaided eye. That is, it is a gross anatomic term and is not intended to indicate the probable histologic structure of the tumor. Polyps of the rectum and colon vary in size from small excrescences on the mucous surface (fig. 1) to pediculate tumors of varying size (fig. 2). Between these two extremes there are many variations in the gross appearances of these tumors. If histologic examination reveals that the polyp is an adenoma, it is proper to designate the condition as "adenomatosis of the colon." The general employment of the term "adenomatosis" to designate a polyposis of the colon is likely to create confusion unless microscopic examination has revealed the adenomatous nature of the lesion. Not all polyps of the colon are adenomas. The classification of polyps of the colon is