[Amelanotic melanoma. Study of 18 cases].

The authors analyze a retrospective study of 18 cases of amelanotic melanoma, coming from 7 Departments of Dermatopathology, and 3 from private clinics in Brazil, during the period from 1980 through 1987. Nine of the 18 patients were men, and seven were women; 14 of the 18 were caucasian and 2 were blacks. Their average combined age was 56 years, varying from 24 years to 86 years. The average size of the lesions was 2.7 cm. and the location was: extremities = 7, thoracic wall = 5, upper limb = 2, and lower limb = 2. Only 2 cases included in this analyses, didn't have any other additional information about color, age, sex and location. The authors found that amelanotic melanoma is rare, in accordance with the literature. They point out, that the rarity or the lack of the melanic pigment within the tumors cells, makes the clinical diagnosis much more complex.