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

Background: Acral melanomas are known to have a low frequency of mutation, in contrary to higher mutation. Recently, VE1 immunostaining was reported to have a good correlation with mutation status.

Objective: We aimed to evaluate the clinicopathological features of -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 mutation status. We also determined the correlation of VE1 immunohistochemical staining with mutation status.

Results: Among 19 acral melanomas with 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 V600E mutation (sensitivity 100%), and negative in 4 cases of non-V600E mutation. However, VE1 immunostaining was negative in all 22 patients with wild-type.

Conclusion: VE1 immunostaining had a good correlation with V600E mutation status.