Clinical data such as location and size of tumor and histopathological diagnosis seem to be good predictors of outcome in canine melanomas. The behavior of these tumors is site-dependent.
The aim of this study was to determine whether DNA content, parameters of cell cycle kinetics, and mitotic activity correlate with location and pathological diagnosis. In 65 melanomas from archival material, the DNA content was quantified by means of flow cytometry.
Six samples, in which the coefficient of variation (CV) of the G0/G1 half peak was > 6%, were excluded. DNA aneuploid tumor cells were found in 33.9%.
All cutaneous melanomas, regardless of histopathological signs of malignancy, were DNA diploid and their mitotic activity was low. No significant correlations between cell cycle parameters and location of the melanomas have been proved.
These results indicate that increased DNA content and percentage of G2/M phase in dog melanomas may be associated with malignant properties and with location in nail bed and in oral cavity.