Characterization of human adenomatous polyps of the colorectal bowel by means of DNA distribution patterns

64 human adenomatous polyps of the colorectal bowel were investigated by histological examination and by flow cytometrical analysis providing DNA distribution patterns. The histological investigation yielded tubular adenomas (TA) in 41 and tubulo-villous adenomas (TVA) in 23 cases. Epithelial dysplasia or carcinomatous degeneration was found in 23 TA and in 11 TVA. Cell cycle stage analysis revealed no different values for TA and TVA without dysplasia, neither for TA and TVA with mild to moderate dysplasia. TVA with severe dysplasia exhibited a significantly higher proportion of cells with G2M phase DNA content than cases without dysplasia or mild to moderate dysplasia. TA and TVA without dysplasia were characterized by diploid DNA distribution patterns. TA with dysplasia showed aneuploid DNA stem lines in 4 of 20 cases, carcinomas arisen from TA in all 4 cases investigated. TVA with dysplasia were characterized by aneuploid DNA stem lines in 1 of 8 cases, carcinomas arisen from TVA in all 4 cases examined. It may be concluded that the DNA distribution patterns do not attribute different biological values to TA and TVA, 2 groups of adenomatous polyps which are characterized by different histological criteria.