We report a case of Turcot's syndrome in a 20-year old man with multiple 
adenomatous polyps of the colon and glioblastoma multiforme. Detailed 
histopathological study of all 25 polyps removed from his colon confirmed the 
distinct morphological and numerical features of the colonic polyposis in 
Turcot's syndrome. Moreover, 45% of the total polyps and all polyps with a 
diameter exceeding 2 cm showed malignant transformation, indicating the 
precancerous nature of these polyps. These findings are discussed together with 
data obtained from a literature review of 32 histopathologically confirmed cases 
of Turcot's syndrome with reference to the possible heterogeneous nature of the 
syndrome at the present time. The current views on the relationship of Turcot's 
syndrome to other polyposis coli syndromes are presented.