DNA content of normal and neoplastic urothelial cells. A comparative cytofluorometric and cytomorphologic study.

In search for suitable parameters to detect neoplastic urothelial cells in Acriflavine-Feulgen-SITS stained specimen we compared the cytofluorometric DNA content with the morphology of normal urothelial cells (bladder scrapings) and neoplastic urothelial cells from grade 1, 2, 3 and 4 tumors. An individual normal urothelial cell could not be distinguished from a grade 1 tumor cell, neither morphologically nor fluorometrically. However, the shape of the histograms of DNA measurements of the cell populations of respectively normal bladder scrapings and grade 1 tumors differs. It is postulated that also morphometry of these cell populations may be of some aid to distinguish well-differentiated neoplastic cells from normal urothelial cells. Seventy-one percent of the morphologically malignant cells in the grade 2,3 and 4 tumor samples could be identified by applying the combined parameters: high DNA content (greater than 5 C) and nuclear-cytoplasmic ratio (greater than 0.5) and all grade 2, 3 and 4 tumor samples contained cells which were objectively classified as malignant. Using the same parameters morphologically malignant cells could be distinguished from normal, polyploid umbrella cells, thus these malignant cells are detectable objectively without using chromatin pattern as parameter.