Differences between mutation profile of acral nevi and acral melanoma
July 27, 2021
Abstract
Importance:
Acral skin may develop nevi, but their mutational status and association with acral melanoma is unclear.
Objective:
To perform targeted next-generation sequencing on a cohort of acral nevi to determine their mutational spectrum.
Design, Setting, and Participants:
Acral nevi specimens (n = 50) that had been obtained for diagnostic purposes were identified from the pathology archives of a tertiary care academic cancer center and a university dermatology clinic. Next-generation sequencing was performed on DNA extracted from the specimens, and mutations called. A subset of samples was stained immunohistochemically for the BRAF V600E mutation.
Results:
A total of 50 nevi from 49 patients (19 males and 30 females; median [range] age, 48 [13-85] years) were examined. Analysis of the sequencing data revealed a high prevalence of BRAF mutations (n = 43), with a lower frequency of NRAS mutations (n = 5). Mutations in BRAF and NRAS were mutually exclusive.
Conclusions and Relevance:
In this cohort study, nevi arising on mostly sun-protected acral skin showed a rate of BRAF mutation similar to that of acquired nevi on sun-exposed skin but far higher than that of acral melanoma. These findings are in contrast to the well-characterized mutational landscape of acral melanoma.
Source:
Smalley KSM, Teer JK, Chen YA, et al. A Mutational Survey of Acral Nevi. JAMA Dermatol. 2021;157(7):831–835. doi:10.1001/jamadermatol.2021.0793