DNA ploidy and proliferation characteristics of bowel polyps analysed by flow cytometry compared with cytology and histology.

56 human adenomatous bowel polyps and 44 samples of macroscopically unchanged bowel mucosa taken at a distance of 2-10 cm from the polyp were investigated by histology, cytology, and flow cytometry in respect to their dysplasia grade and DNA distributions. 30 human adenomatous polyps of the same localization were investigated by histology and flow cytometry; in 14 cases in addition to the DNA-patterns per se their changes mediated by heparin, a polyanion, were recorded. Histological and cytological investigations revealed mild dysplasia in 25 cases, moderate dysplasia in 43 cases and severe dysplasia in 18 cases. DNA aneuploidy was correlated with the histological finding of mild dysplasia three times, of moderate dysplasia twice and severe dysplasia five times. All other cases, also macroscopically unchanged bowel mucosa revealed DNA diploidy. In these diploid cases, cell cycle stage analysis yielded a higher proportion of cells in S-phase and G2M phase in adenomas with severe dysplasia in comparison to adenomas with moderate and mild dysplasia (P less than 0.05). Macroscopically unchanged bowel mucosa showed about the same values as adenomas with mild dysplasia. The heparin mediated increase in fluorescence intensity is different for adenomas with mild and moderate dysplasia, and attributed to the latter a higher proliferative activity (P less than 0.05).