Primary cutaneous melanoma of the scalp: Patterns of clinical, histological and epidemiological characteristics in Brazil

BACKGROUND/OBJECTIVES: Scalp melanoma is a subgroup of melanomas on the head and neck, historically associated with worst prognosis. Knowledge of the usual presentation of scalp melanoma can help to understand the reasons for the poor outcomes of treatment. This is the first publication to describe the clinical, histopathological and epidemiological profile of patients with scalp melanoma in a Latin American population. METHODS: A cross-sectional study was performed of all primary cutaneous melanoma seen by the A.C.Camargo Cancer Center between 2008 and 2018, using an electronic health records to access clinical and pathology data. RESULTS: When compared to trunk and limbs, increasing age is expected for patients with scalp melanoma (10.865; CI (95%) = [8.303; 13.427]). Regarding risk of invasion, scalp melanomas have a higher chance to be invasive than in situ (OR = 1.783; CI (95%) = [1.196; 2.657]) and present with higher Breslow thickness (OR = 3.005; CI (95%) = [2.507; 3.601]). Scalp site was significantly associated with male sex (OR = 3.750; CI (95%) = [2.533; 5.554]), perineural invasion (OR = 13.739; CI (95%) = [5.919; 31.895]), ulceration (OR = 2.311; CI (95%) = [1.488; 3.588]), and mitosis (OR = 2.366; CI (95%) = [1.701; 3.292]), when compared to trunk and limbs melanoma. CONCLUSION: In the present study, head and neck melanomas represented 14.9% of all melanomas, a frequency slightly lower than that described in the literature and the mean age of melanoma on the scalp found was lower than that reported in the literature. These results could be explained by the demographic characteristics of Brazil, which has a population with a lower life expectancy compared to the European and North American population. Scalp melanomas occurred in older men, were diagnosed with greater Breslow thickness and were associated with the presence of perineural invasion, mitosis and ulceration.