Origin and treatment of malignant melanoma.

Studies in man and other animals indicate that tendency to development of malignant melanoma may be congenital. Dark-skinned races have a lower incidence than light-skinned races.Sixty-five per cent of all malignant melanomas arise from possibly congenital moles; in over half of the 57 cases included in this study the patient observed gross change in the precurrent lesion. Trauma, even a single blow, is often the cause of malignant change. Excision of all pigmented moles subject to trauma is urged as a means of reducing the incidence of this highly malignant lesion. Biopsy of suspected lesions, followed by excision of a wide area and adjoining lymph nodes if indicated, is the only adequate treatment. The removal of hirsute moles for cosmetic reasons is discussed.