Epidemiology and clinical features of malignant melanoma. Analysis of 274 cases

Background: Malignant melanoma (MM) is the most fatal cutaneous neoplasm. Its incidence is increasing progressively, which cannot be explained only by early diagnosis. Chilean population, due to the geography of the country, has a very varied solar exposure. Aim: To know the incidence of MM in a Chilean population, according to the level of sun exposure and to describe its clinical and histopathological characteristics. Material and Methods: Two hundred seventy-four surgeries for malignant melanoma with histological confirmation, carried out between 2016 and 2018 in an oncological institute were included. Results: The annualized incidence of MM was 13.83 cases per 100,000 people over 15 years of age in the 2016-2018 period. The geographical distribution of the incidence did not have a clear relationship with sun exposure. The most frequent locations of the primary lesions were trunk, head/neck and lower limb. Sixty-one per cent of cases were invasive MM; lesion thickness and presence of ulceration were associated with a higher risk of sentinel node involvement. Conclusions: No association between the level of sun exposure and the incidence of MM was observed in this study.