NRAS Q61R and BRAF G466A mutations in atypical melanocytic lesions newly arising in advanced melanoma patients treated with vemurafenib.

There appears to be development or accelerated growth of atypical melanocytic lesions in the setting of BRAF inhibition. Our results underscore the need for careful surveillance for melanocytic lesions in patients on BRAF inhibitor therapy and shed light on potential mechanisms for melanoma pathogenesis in the context of BRAF pathway blockade. Further studies are warranted to show a causal relationship.