biostudies-literatureUnknown31(10)Tavares TSFundação de Amparo à Pesquisa do Estado de Minas GeraisConselho Nacional de Desenvolvimento Científico e TecnológicoCoordenação de Aperfeiçoamento de Pessoal de Nível SuperiorPró-Reitoria de Pesquisa, Universidade Federal de Minas Gerais<h4>Objective</h4>Oral melanocytic nevi (OMN) are histologically similar to skin nevi; however, they are much rarer and not always related to sun exposure. This study aimed to characterize the histopathological, immunohistochemical, and molecular features of OMN in sun-exposed (vermilion lip) and sun-protected (intraoral) regions.<h4>Method</h4>Cross-sectional study on 14 intraoral and 20 vermilion lip OMN. Hematoxylin-eosin, immunohistochemistry for TRP2 and MiTF, and RT-qPCR for TRP2 and MiTF were used to assess histopathology, protein, and mRNA expression, respectively. Statistical analysis was performed.<h4>Results</h4>Intramucous and blue nevi are the most frequent histological subtypes. Intraoral lesions predominantly affect Brown or Black individuals (64.3%), presenting mostly as maOral diseases2906-2913https://www.ebi.ac.uk/biostudies/studies/S-EPMC12721702biostudies-literatureCharacterization of Oral Melanocytic Nevi in Sun-Exposed and Sun-Protected Regions.PMC12721702Tarquinio SBCDiniz MGJohann ACBRCaldeira PCMeirelles DPVasconcelos ACUde Aguiar MCFGomez RSTavares TSda Costa AASfalseCharacterization of Oral Melanocytic Nevi in Sun-Exposed and Sun-Protected Regions.<h4>Objective</h4>Oral melanocytic nevi (OMN) are histologically similar to skin nevi; however, they are much rarer and not always related to sun exposure. This study aimed to characterize the histopathological, immunohistochemical, and molecular features of OMN in sun-exposed (vermilion lip) and sun-protected (intraoral) regions.<h4>Method</h4>Cross-sectional study on 14 intraoral and 20 vermilion lip OMN. Hematoxylin-eosin, immunohistochemistry for TRP2 and MiTF, and RT-qPCR for TRP2 and MiTF were used to assess histopathology, protein, and mRNA expression, respectively. Statistical analysis was performed.<h4>Results</h4>Intramucous and blue nevi are the most frequent histological subtypes. Intraoral lesions predominantly affect Brown or Black individuals (64.3%), presenting mostly as ma2025-01-01T00:00:00Z2025 Oct2026-06-06T05:28:38.099Z2026-05-26T03:12:11.362ZS-EPMC127217024050956310.1111/odi.15404