Abstract Context.—Cutaneous melanoma in childhood (CMC) is rare; therefore, its prognostic factors and biologic behavior, and the effectiveness of adjuvant techniques for CMC remain mostly unknown. Objective.—To review the most useful, evidence-based practice criteria for establishing the diagnosis of CMC, for which universally accepted criteria are lacking, in order to facilitate the interpretation and comparison of the results from different institutions, and to perform systematic reviews and meta-analysis. Data Sources.—A comprehensive review of the most relevant previous single-institution series reported in the literature since 1990, including our cumulative experience of 137 cases of primary cutaneous and mucosal melanoma in patients younger than 18 years. Special characteristics of melanoma in children are discussed, regarding clinical settings and risk factors, helpful histologic features, and immunohistochemical patterns for diagnosis and prognosis. Conclusions.—Careful analysis of histologic fea...