Letter to the Editor - The BRAF V600E Mutation is Not Present in All Cells of the Primary Melanoma and May Not Be Detected in All Metastatic Sites

Abstract

The invention of targeted therapy for advanced stage melanoma has made it necessary to perform a mutation analysis of each melanoma case in order to detect the BRAF V600E mutation required for the prescription of selective BRAF inhibitors. In this new clinical context it is important to realize that the tumour seeds may come from different tumour clones and thus not all carry the mutation. We present an illustrative case that shows this phenomenon and discuss the consequences for clinical management in case of possible false negative mutation testing.