Is There More Than One Road to Nevus-Associated Melanoma?

Roberta Vezzoni,Claudio Conforti,Chiara Retrosi,Roberta Giuffrida,Giovanni Magaton-Rizzi,Silvia Vichi,Nicola Di Meo,Maria Antonietta Pizzichetta,Iris Zalaudek

doi:10.5826/dpc.1002a28

Roberta Vezzoni, Claudio Conforti + Show 7 more

Open Access

https://doi.org/10.5826/dpc.1002a28

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Abstract

The association of melanoma with a preexisting nevus is still a debated subject. Histopathological data support an associated nevus in approximately 30% of all excised melanomas. The annual risk of an individual melanocytic nevus becoming malignant is extremely low and has been estimated to be approximately 0.0005% (or less than 1 in 200,000) before the age of 40 years, to 0.003% (1 in 33,000) in patients older than 60 years. Current understanding, based on the noticeable, small, truly congenital nevi and nevi acquired early in life, is that the first develops before puberty, presents with a dermoscopic globular pattern, and persists for the lifetime, becoming later a dermal nevus in the adult. In contrast, acquired melanocytic nevi develop mostly at puberty and usually undergo spontaneous involution after the fifth decade of life. The purpose of this review is to analyze the data of the literature and to propose, on the basis of epidemiological and clinical-dermoscopic characteristics, a new model of melanogenesis of nevus-associated melanoma.

Highlights

The association of melanoma with a preexisting nevus is still a debated subject
The results showed that the presence of irregular globules, streaks, and a negative pigment network were significantly related to Nevus-associated melanoma (NAM)
Current literature, and clinical evaluation, it can be assumed that there are 2 different types of NAM: a melanoma that arises in the center of the mole and a melanoma that grows next to the mole

Summary

Introduction

The association of melanoma with a preexisting nevus is still a debated subject. Histopathological data support an associated nevus in approximately 30% of all excised melanomas [1]. It must be acknowledged that these numbers do not reflect the true frequency of this event, as histopathological studies rely on selection bias of excised, suspicious lesions. The annual risk of an individual melanocytic nevus becoming malignant is extremely low and has been estimated to be approximately 0.0005% (or less than 1 in 200,000) before the age of 40 years, to 0.003% (1 in 33,000) in patients older than 60 years [2,3]. Since many studies propose a direct correlation between the number of moles and melanoma development (roughly 2- to 14-fold), efforts to curb the rise in melanoma have centered on the detection of early changes in melanocytic nevi [2].

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Conclusion