M VE1 Antibody Immunoreactivity in Normal Anterior Pituitary and Adrenal Cortex Without Detectable BRAF V600E Mutations

Objectives: The VE1 monoclonal antibody was developed to recognize the V600E mutation in BRAF, which is found in various tumors. Methods: We report that the VE1 antibody stains normal anterior pituitary gland and adrenal cortex, which lack detectable BRAF V600E mutations. Results: Staining with the VE1 antibody was seen in the adenohypophysis and correlated well with adrenocorticotropic hormone (ACTH)–positive cells. ACTH-positive cells were typically most concentrated in the central mucoid wedge and pars intermedia, and VE1 staining was strong in these regions. Moreover, VE1 staining was seen in ACTH-expressing pituitary adenomas without detectable BRAF mutations. VE1 staining of the adrenal cortex wa