Malignant melanoma in association with phototherapy

A 54-year-old Caucasian male suffering from psoriasis had been treated in 1978 and 1980 with PUVA (cumulative UVA dose 492.5 J/cm2) and from 1980 to 1989 with UVB (cumulative UVB dose 264.5 J/cm2). Other occasional treatment had comprised the topical administration of glucocorticosteroids, dithranol or tar. In 1989, on the upper part of the patient's back a newly developed pigmented skin lesion was excised under the clinical diagnosis of a pigmented, dysplastic nevus. Histological examination revealed a superficial spreading malignant melanoma (0.4 mm thick, Clark level II). In this case, exposure to high cumulative doses of therapeutic UV irradiation might have played an etiological role for the development of malignant melanoma.