Primary oral melanoma: population-based incidence.

Primary oral melanoma (POM) is a rare form of melanoma, generally diagnosed at a late stage and has poor prognosis. Epidemiological information has scarcely been reported in the literature over the past 40 years. Analyzing the Cancer Incidence in Five Continents volume IX (CI5-IX) database we found a total of 124,436 oral cavity cancers reported from all population-based cancer registries and 319 cases of POM reported by 67 cancer registries. To our knowledge this is the largest number of POM cases analyzed and accounts for 0.26% of all oral cavity cancers. ASR(W) for POM do not exceed 0.01 per 100,000 persons-year in all regions. The most common anatomic sites were palate (47%) and gum (27.6%) and a detailed oral mucosa examination and biopsies of nodular or macular lesions in these sites, especially on elderly patients, is advised to be routinely performed.