Turcot syndrome and its characteristic colonic manifestations.

The reported clinical manifestations of Turcot syndrome were studied to determine whether these corresponded to those of Turcot's original cases. Among the patients with well-documented colonic lesions, the colonic lesions were classified into three groups. First, there was a main group in which colonic lesions had the following characteristics that coincided with those of Turcot's original cases: a low number of polyps (20-100), large polyps over 3 cm in diameter, and complication by colonic cancer during the second or third decades. In the second group, the patients had too few polyps to be diagnosed as polyposis. The third group included patients with numerous colonic polyps similar to those of familial polyposis coli. The recognition of these characteristics of colonic lesions may lead to early detection of glioma in the asymptomatic period.