DNA ploidy and nuclear morphometric variables for the evaluation of melanocytic tumors in dogs and cats

Objective—To determine the prognostic importance of the DNA content and nuclear morphometric variables in melanocytic tumors of cats and dogs. Sample Population—27 melanocytic tumors of dogs and cats. Procedures—Biopsy specimens were investigated by quantitative image analysis after the Feulgen staining method. The DNA content (index), nuclear diameter, ploidy balance, proliferation index, hyperploidy, and growth fraction (Ki67) were measured. Using 1- way ANOVA and a Pearson correlation test, the relationships between the different variables were tested. Their role in the prognosis in affected dogs and cats was estimated using the Cox regression test with respect to 6 months postoperative survival rate. Results—Significant correlations were found between DNA index and ploidy balance and proliferation index. A significant correlation was also found between hyperploidy and DNA index, and between ploidy balance and proliferation index. Significant differences were found between histologically malignant and ...