Absence of BRAF mutation in pheochromocytoma and paraganglioma.

Pheochromocytomas and Paragangliomas (PHEO/PARA) are rare endocrine tumors originating from the adrenal medulla. More than 20 genes are involved in the tumorigenesis of these tumors, but a substantial part of the causative genetic events remains unexplained. A recent study has reported the presence of the activating BRAF V600E mutation in PCC, suggesting a role for BRAF activation in tumor development. Other studies have not find this mutation. This study investigates the occurrence of the BRAF V600E mutation in these tumors.A cohort of 64 PHEO/PARA were screened for the BRAF V600E mutation using direct Sanger sequencing and QRT-PCR.All cases investigated displayed wild-type without V600E BRAF mutationTaken together with all previously screened tumors up to date, only 1 V600E BRAF mutation has been found among 427 PCCs. These findings imply that the V600E BRAF mutation is a rare event in PHEO/PARA.