The ultrastructure of malignant melanomas. Observations on seven cases

Seven cases of human cutaneous malignant melanomas, some of them associated with distant metastases, were analyzed by electron microscopy. The obtained results indicate that the polymorphism of melanosomes can not be used to distinguish between melanomas developed on Dubreuilh's precancerous melanosis and those formed on nevi. The features of tumoral cells in pigmented tumors were different from those of cells within unpigmented tumors, and there were no cytologic differences between the primary tumor and metastases.