Radiological features of familial polyposis coli: grouping by polyp profusion.

The radiological features of familial polyposis coli (FPC) were studied in 60 patients by double-contrast barium enema examinations. When classified by profusion of polyps, cases fell into two groups: the profuse type and the sparse type. The radiologically determined boundary range distinguishing these types was 6-9 polyps/cm2 in adult patients and 3-6 in children. But on grouping the FPC patients by size of the polyps, one group of 34 cases had one or more polyps of more than 1 cm diameter, and in 16 of this group, one or more advanced cancers were histologically demonstrated; whereas in the group of 20 patients, in which the lesions were 5 mm or less, no malignancy was detected. In contrast to cases of the sparse type, in which the size of the polyps bore no relation to age, all cases of the profuse type who were 15 years old or more had polyps more than 1 cm in diameter.