Mutational status of nevus-associated melanomas.

Introduction Melanoma origin has always been a debated subject, as well as the role of adjacent melanocytic nevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a nevus. Methods Sixty-one melanomas found in association with a preexisting nevus were mi...

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Authors: Shitara, Danielle, Tell Martí, Gemma, Badenas Orquin, Celia, Enokihara, MM., Alós i Hernández, Llúcia, Larque, A.B., Michalany, Nilceo, Puig Butillé, Joan Anton, Carrera Álvarez, Cristina, Malvehy, J. (Josep), Puig i Sardà, Susana, Bagatin, E.
Format: article
Status:Versión aceptada para publicación
Publication Date:2015
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/106731
Online Access:https://hdl.handle.net/2445/106731
Access Level:Open access
Keyword:Melanoma
Oncologia
Càncer
Mutació (Biologia)
Oncology
Cancer
Mutation (Biology)
Description
Summary:Introduction Melanoma origin has always been a debated subject, as well as the role of adjacent melanocytic nevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a nevus. Methods Sixty-one melanomas found in association with a preexisting nevus were microdissected, after careful selection of cell subpopulations and submitted to Sanger sequencing of the BRAF, NRAS, C-KIT, PPP6C, STK19 and RAC1 genes. Each gene was evaluated twice in all samples by sequencing or by sequencing and another confirmation method, allele-specific fluorescent polymerase chain reaction (PCR) and capillary electrophoresis detection, or by SNaPshot Analysis. Only mutations confirmed via two different molecular methods or twice by sequencing were considered positive. Results The majority of cases presented concordance of mutational status between melanoma and the associated nevus for all 6 genes (40/60; 66.7%). Nine cases presented concomitant BRAF and NRAS mutations, including one case, in which both the melanoma and the adjacent nevus harbored V600E and Q61K double mutations. In two cases, both melanoma and associated nevus, located on acral sites were BRAF mutated, including an acral lentiginous melanoma. Conclusions This is the largest nevus-associated melanoma series molecularly evaluated to our knowledge. The majority of melanomas and adjacent nevi in our sample share the same mutational profile, corroborating the theory that the adjacent nevus and melanoma are clonally related and that melanoma originated within a nevus.