Sensitivity and Usefulness of VE1 Immunohistochemical Staining in Acral Melanomas with BRAF Mutation

BACKGROUND: Acral melanomas are known to have a low frequency of BRAF mutation, in contrary to higher KIT mutation. Recently, VE1 immunostaining was reported to have a good correlation with BRAF mutation status. OBJECTIVE: We aimed to evaluate the clinicopathological features of BRAF-mutated acral melanomas and validate the correlation of the VE1 immunohistochemical stains in those cases. METHODS: The clinical features (age, sex, anatomical site), and histopathological characteristics of 41 patients with acral melanoma were evaluated. We performed a next-generation sequencing to detect BRAF mutation status. We also determined the correlation of VE1 immunohistochemical staining with BRAF mutation status. RESULTS: Among 19 acral melanomas with BRAF mutation, common histopathological subtype was acral lentiginous melanoma (8/19, 42%) and nodular melanoma (8/19, 42%) and superficial spreading melanoma (3/19, 16%) followed. VE1 immunostaining results were positive in all 15 cases with BRAF V600E mutation (sensitivity 100%), and negative in 4 cases of BRAF non-V600E mutation. However, VE1 immunostaining was negative in all 22 patients with BRAF wild-type. CONCLUSION: VE1 immunostaining had a good correlation with BRAF V600E mutation status.