[Epidemiology and prognosis of subungual melanoma].

Among a total of 2038 cases of malignant melanoma, 42 tumours (approximately 2%) were located sub- and periungually. The matrices of thumbs and halluces were primarily affected. Girls and women were more frequently affected than boys and men, and a broad "pyramid of age" was obvious. The mean age for both sexes was 61 years. A mean of 1.5-2 years elapsed between the appearance of the first symptoms and establishment of a definitive diagnosis. Pigmented tumours were recognized earlier than non-pigmented ones. The prognosis in melanoma of the nail has usually been found to be poor. The curves for both survival and recurrences display an initial steep downward course. A flatter course is noted for the survival curve beyond 24 months postoperatively and for the survival curve beyond 48 months after surgery. The 5-year disease-free survival rate following operative removal of the tumour or amputation of the digit is 0.50% for subungual melanoma of the hand and 0.31% for subungual melanoma of the foot. By 10 years after operative removal of the tumour, 43% of the patients with subungual melanoma of the feet are still free of disease. Similar differences are found in the length of survival. The 5-year survival rate is 0.57 for subungual melanoma of the hand and 0.48 for melanoma of the foot. The 10-year survival rates, however, are 0.41 and 0.22, respectively. Significant differences between hand and foot cannot be verified in the rate of subungual melanoma.