Cormican D, et al. - Given the great clinical significance of identification of activating mutations of BRAF in metastatic melanoma in view of the available targeted therapies, researchers assessed the frequency with which BRAF status differs between primary and metastatic sites. Study participants included 219 individuals with melanoma who had BRAF testing in their institution between 2011 and 2016. For PCR and immunohistochemical assessment, paired primary and metastatic specimens were available for 53 participants. Rarely, a discordance of BRAF mutational status was observed between primaries and metastases. The investigators found that, on account of a low tumor volume, initial PCR testing provided a false negative result, as strongly suggested by immunohistochemistry in one case. This finding supported the use of primary tumor in cases where tissue is difficult to obtain from a metastasis or unavailable.