Cutaneous melanoma (CM) is an increasingly significant public health concern. Due to alarming mortality rates and escalating incidence, it is crucial to understand its etiology and identify emerging biomarkers for improved diagnosis and treatment strategies. This review aims to provide a comprehensive overview of the multifactorial etiology of CM, underscore the importance of early detection, discuss the molecular mechanisms behind melanoma development and progression, and shed light on the role of the potential biomarkers in diagnosis and treatment. The pathogenesis of CM involves a complex interplay of genetic predispositions and environmental exposures, ultraviolet radiation exposure being the predominant environmental risk factor. The emergence of new biomarkers, such as novel immunohistochemical markers, gene mutation analysis, microRNA, and exosome protein expressions, holds promise for improved early detection, and prognostic and personalized therapeutic strategies.

Proliferative activity in cutaneous melanomas can be appreciated both histopathologically by counting mitotic figures and immunohistochemically through the Ki67 index, but the prognostic value of each method is still a matter of debate. In this context, we performed a retrospective study on 33 patients diagnosed with cutaneous melanomas between 2013 and 2018 in order to evaluate progression-free survival and overall survival. Multivariate Cox proportional hazards regression was performed by considering both clinical histopathological and immunohistochemical features. The mitotic rate was significantly independently associated with both outcomes, while the Ki67 index was not an independent prognostic factor. However, the Ki67 predictive accuracy could be improved by establishing both a cut-off value and a standardized protocol for evaluating its expression. Until these desiderata are met, the mitotic rate remains superior to the Ki67 index for predicting prognosis in cutaneous melanomas, as also has the advantage of being easily interpreted in a standard histopathological examination regardless of the pathologist’s experience and with no further financial expenses. Importantly, this is one of very few articles that has shown perineural invasion to be an independent prognostic factor for both progression-free survival and overall survival in cutaneous melanomas. As a consequence, this parameter should become a mandatory feature in the histopathological evaluation of cutaneous melanomas as it can improve the identification of patients who are at high risk for disease progression.

Intermediate-thickness melanomas display highly variable outcomes influenced by both clinical and histopathological characteristics. This study investigates several clinicopathological prognostic factors for pT3 cutaneous melanomas, focusing on a novel parameter, the width of invasion. This is a retrospective study of 49 patients diagnosed with cutaneous melanoma between 2012 and 2018 who were followed up for at least five years. We evaluated the age, gender, tumor location, Breslow depth of invasion, width of invasion, mitotic index, the presence/absence of ulceration, regression, microsatellites, lymphovascular invasion, and perineural invasion for their association with disease progression and survival. Cox univariate analysis revealed that progression-free survival (PFS) was significantly associated with age, depth of invasion, width of invasion, lymphovascular invasion, microsatellites, and perineural invasion. Overall survival (OS) was significantly associated with age, depth of invasion, width of invasion, microsatellites, and perineural invasion. Through multivariate Cox proportional hazards regression, the only factor associated with both PFS and OS was the width of the invasion. This is one of the few studies to assess the width of invasion and we have demonstrated that this parameter could become an important prognostic factor for cutaneous melanomas.