The DNA content and nuclear size in normal, dysplastic and carcinomatous laryngeal epithelium. A spectrophotometric study.

The aim of the present study was to obtain a more objective evaluation of nuclear hyperchromasia and polymorphism in laryngeal epithelium. The method is based on a photometric assay of nuclear size and DNA content in Feulgen stained slides. The DNA content of hyperchromatic nuclei should exceed the mean for nuclei of normal epithelium by more than twice the standard deviation. In comparison with lymphocytes (2N) the DNA content in hyperchromatic nuclei corresponds to 3.3 N. The mean DNA contents of normal, dysplastic and carcinomatous laryngeal nuclei were 69, 71 and 118 A.U. The mean nuclear area for normal, dysplastic and carcinomatous epithelial cells were 48, 41 and 73 micrometer2. The higher the degree of atypia displayed by the cells the greater was the variability of the DNA content and the nuclear size. The investigation shows that the method may provide a more objective basis for evaluating hyperchromasia and polymorphism.