The epidermal melanocytes in patients with cutaneous malignant melanoma. A transmission electron microscopic investigation.

The epidermal melanocytes were studied in biopsies from clinically normal skin removed at various distances from cutaneous malignant melanomas. Melanocytes with some ultrastructural changes were found in a number of patients, which can be either contingent on genetic or inter/extra cellular factors. It is possible that cells with these changes are more instable and more easily transformed to malignant cells by external influence. Malignant cells were not demonstrated in either the epidermis or the dermo-epidermal junction. Activation was seen of the epidermal melanocytes lying in the immediate neighbourhood of the superficially spreading melanomas, which would suggest that this type of tumour is presumably able to influence the melanocytes. The most pronounced changes in the whole of the melanocyte system was found in patients with multiple melanomas, and in a patient with metastasizing malignant melanoma.