Sun exposure and melanomas on sun-shielded and sun-exposed body areas.

Malignant melanoma is a tumor that arises from melanocytes and accounts for around 4% of all malignancies in Europe and Northern America and for about 11% in Australia and New Zealand. About 10% of primary melanomas arise from sites not exposed to sun. Acral lentiginous melanoma, mucosal melanoma (in the oral cavities, nasal sinuses, genital tract and rectum) and uveal melanoma are all on non-sun-exposed tissues. Epidemiologic aspects ofmelanomas on non-sun-exposed areas in comparison with melanomas in sun-exposed areas have been reviewed. We focus on the relationship between melanoma incidence, geographic latitude of residence, race/ethnicity and host factors as well as time trends.