[Melanoma in xeroderma pigmentosum: 12 cases].
BACKGROUND: Xeroderma pigmentosum is a rare genodermatosis, with a defect affecting recovery of ultraviolet-induced damages and characterized by a high rate of malignancies of the exposed skin areas. We studied melanoma features of patients with xeroderma pigmentosum. PATIENTS AND METHODS: A retrospective study of xeroderma pigmentosum patients admitted to the Charles Nicolle Hospital of Tunis between 1973 and 1998. RESULTS: Two hundred sixteen patients with xeroderma pigmentosum were registered. Melanoma was present in 12 patients, 7 females and 5 males. Two patients were sisters. Cutaneous melanoma was found in 8 patients. Four patients presented with metastatic melanoma. The median age for development of the first melanoma was 17.5 years. All of the cutaneous melanomas were found on the face. Lentigo malignant melanoma was reported in 3 cases. The tumors were treated with surgical excision. Except for a melanoma affecting the orbit, characterized by a fatal outcome, no metastases were detected at the different investigations. DISCUSSION: Melanoma occurs frequently in patients with xeroderma pigmentosum, it has been reported in 5.5 p. 100 of cases and 11.3 p. 100 of patients with cutaneous carcinoma. The age of onset was low: 17.5 years. It appeared later than the carcinoma. The location of cutaneous melanoma in face in xeroderma pigmentosum patients indicates that they were caused mainly by sunlight exposure. Lentigo malignant melanoma was the most frequent type. Prognosis is difficult to define owing to the large number of other cutaneous malignancies. Apart from one case of rapidly fatal orbital melanoma, we recorded long survivals even in cases of melanoma revealed by metastases.