Melanoma Arising in a Melanocytic Nevus

Can we manage the melanocytic lesions with peripheral globules according to the grade of dysplasia?

BACKGROUND/OBJECTIVES

Although excision of melanocytic nevi with high-grade dysplasia is recommended by the World Health Organization (WHO), clinical studies investigating the approach based on the grading dysplasia of melanocytic lesions with peripheral globules (PGs) are lacking. We investigated the grades of dysplasia and their distinguishable dermoscopic and clinical features to provide accurate data for managing these lesions.

METHODS

We retrospectively classified histologically confirmed melanocytic lesions with PGs according to the 2018 WHO Classification of Skin Tumours criteria in a university hospital in Turkey. Dermoscopic features, lesions, and patient characteristics were recorded.

RESULTS

Sixty-six lesions of 56 patients were included. After classification, 9.1% (n: 6) of lesions were melanomas, 39.4% (n: 26) were high-grade dysplastic nevi, and 50% (n: 33) were low-grade dysplastic nevi (n: 33, 50%). There was one nevus with no dysplasia (n: 1, 1.5%). Univariate analysis revealed that ≥31 years of age, irregular shape of peripheral globules, black colour, total colour count, and maximum diameter of the lesion were associated with high-grade dysplasia and melanoma. In the multivariate analyses, ≥31 years of age (OR = 3.80, 95% CI, 1.17-12.37), irregular shape of peripheral globules (OR = 3.90, 95% CI, 1.15-13.2), and total colour count (OR = 3.21, 95% CI, 1.2-8.5) were significant predictive factors for the lesions with high-grade dysplasia and melanomas.

CONCLUSIONS

To avoid the underdiagnosis of both melanomas and high-grade dysplastic nevi with PGs, the irregular shape of peripheral globules and multiple colours after the third decade may be useful in making an excision decision. The risk increases every 1-year increase in age. Excision is suggested for all melanocytic lesions with PGs for patients 60 years or older because of the high risk of melanoma and melanocytic nevus with high-grade dysplasia.

The Many Roles of Dermoscopy in Melanoma Detection

Dermoscopy is a non-invasive method of examination that aids the clinician in many ways, especially in early skin cancer detection. Melanoma is one of the most aggressive forms of skin cancer that can affect individuals of any age, having an increasing incidence worldwide. The gold standard for melanoma diagnosis is histopathological examination, but dermoscopy is also very important for its detection. To highlight the many roles of dermoscopy, we analyzed 200 melanocytic lesions. The main objective of this study was to detect through dermoscopy hints of melanomagenesis in the studied lot. The most suspicious were 10 lesions which proved to be melanomas confirmed through histopathology. The second objective of this study was to establish if dermoscopy can aid in estimating the Breslow index (tumoral thickness) of the melanomas and to compare the results to the histopathological examination. We found that the tumoral thickness may be estimated through dermoscopy, but the histopathological examination is superior. To conclude, the aim of this study was to showcase the versatility and many roles of dermoscopy, besides being one of the most important tools for early melanoma diagnosis.

Review: The Key Factors to Melanomagenesis

Melanoma is the most dangerous form of skin cancer that develops from the malignant transformation of the melanocytes located in the basal layer of the epidermis (cutaneous melanoma). Melanocytes may also be found in the meninges, eyes, ears, gastrointestinal tract, genito-urinary system, or other mucosal surfaces (mucosal melanoma). Melanoma is caused by an uncontrolled proliferation of melanocytes, that at first may form a benign lesion (nevogenesis), but in time, it may transition to melanoma, determining what it is named, melanomagenesis. Some tumors may appear spontaneously (de novo melanoma) or on preexisting lesions (nevus-associated melanoma). The exact cause of melanoma may not be fully understood yet, but there are some factors that initiate and promote this malignant process. This study aims to provide a summary of the latest articles regarding the key factors that may lead to melanomagenesis. The secondary objectives are to reveal the relationship between nevi and melanoma, to understand the cause of "de novo" and "nevus-associated melanoma" and highlight the differences between these subtypes.

Cutaneous Melanoma-A Long Road from Experimental Models to Clinical Outcome: A Review

Cutaneous melanoma is a complex disorder characterized by an elevated degree of heterogeneity, features that place it among the most aggressive types of cancer. Although significant progress was recorded in both the understanding of melanoma biology and genetics, and in therapeutic approaches, this malignancy still represents a major problem worldwide due to its high incidence and the lack of a curative treatment for advanced stages. This review offers a survey of the most recent information available regarding the melanoma epidemiology, etiology, and genetic profile. Also discussed was the topic of cutaneous melanoma murine models outlining the role of these models in understanding the molecular pathways involved in melanoma initiation, progression, and metastasis.