BRAF and GNAQ mutations in melanocytic tumors of the oral cavity.

OBJECTIVE

The genetic factors participating in oral melanoma evolution have not been studied extensively. We aimed to analyze the prevalence of BRAF and GNAQ mutations in a series of oral melanocytic tumors, nevi, and melanomas.

STUDY DESIGN

The study group consisted of 4 melanomas and 10 nevi (6 intramucosal, 4 blue nevi). DNA was extracted from paraffin-embedded tissue sections, and mutations in GNAQ and BRAF were analyzed with the use of mass spectrometery.

RESULTS

V600E point mutation was identified in the BRAF gene in 3 intramucosal nevi and in 2 melanomas. Only 1 blue nevus harbored the GNAQ209 mutation. None of the BRAF-positive samples harbored GNAQ mutations.

CONCLUSIONS

The finding of BRAF mutations in oral benign and malignant melanocytic lesions points to a potential initiating role of BRAF in malignant transformation, which may have important therapeutic implications as those with BRAF mutations may benefit from specific treatment using RAF inhibitors.