Melanoma: epidemiology, risk factors, pathogenesis, diagnosis and classification.

This article reviews epidemiology, risk factors, pathogenesis and diagnosis of melanoma. Data on melanoma from the majority of countries show a rapid increase of the incidence of this cancer, with a slowing of the rate of incidence in the period 1990-2000. Males are approximately 1.5-times more likely to develop melanoma than females, while according to other studies, the different prevalence in both sexes must be analyzed in relation with age: the incidence rate of melanoma is grater in women than men until they reach the age of 40 years, however, by 75 years of age, the incidence is almost 3-times as high in men versus women. The most important and potentially modifiable environmental risk factor for developing malignant melanoma is the exposure to ultraviolet (UV) rays because of their genotoxic effect. Artificial UV exposure may play a role in the development of melanoma. The most important host risk factors are the number of melanocytic nevi, familiar history and genetic susceptibility. A patient with a personal history of melanoma must be considered at greater risk for subsequent melanoma. Indeed approximately 1-8% of patients with prior history of melanoma will develop multiple primary melanomas. We herein review the dermatological diagnosis and classification of melanoma.