A melanoma in a dysplastic nevus contained a phenotype-genotype disagreement confounding the exclusive significance of BRAF and NRAS mutations in melanoma pathogenesis, according to Dr. Jean-Marie Tan and associates.
A man in his 50s was diagnosed with a melanoma in a dysplastic nevus after being admitted with a irregularly pigmented melanocytic lesion. Microbiopsy specimens were taken across the lesion and genotyping was carried out on DNA samples for BRAF and NRAS mutations. The melanoma showed only BRAF wild-type, while the dysplastic nevus showed both BRAF wild-type and BRAF V600E mutations. Sequencing in all DNA samples revealed NRAS wild-type genotype, the researchers found.
These conflicting results indicate further studies are required to investigate the importance of other candidate genes linked to melanomagenesis, the investigators concluded.
Read the full article at JAMA Dermatology (doi:10.1001/jamadermatol.2014.3775).