DNA ploidy in human colorectal adenomas.

The DNA content of 101 colorectal adenomas of various histologic types resected from 83 patients was determined by image cytometric measurements in order to investigate if a correlation between DNA ploidy and particular histomorphologic features exists and if DNA measurements can be of additional diagnostic value. Overall, 67 of 101 (66%) adenomas showed an aneuploid DNA distribution pattern, including 8 of 19 (42.1%) mildly atypical, 32 of 48 (66.7%) moderately atypical and 27 of 34 (79.4%) severely atypical adenomas. Correlating DNA content with the histologic type, 17 of 42 (40.5%) tubular, 28 of 37 (75.7%) tubulovillous and all 22 villous adenomas exhibited aneuploid DNA histograms. Aneuploidy was also observed more frequently in larger adenomas. The results show a good correlation between tumor size, histomorphologic features and DNA content. The most remarkable observation is that as many as 42% of the adenomas histomorphologically considered mildly atypical exhibited aneuploidy. Since aneuploidy has been demonstrated to indicate premalignant or malignant cellular alterations, DNA image cytometry is suggested for providing valuable additional information on the diagnosis of colorectal adenomas.