MAP4K3 and Hyperkeratosis: Microscopic examination demonstrates hyperkeratosis, papillomatosis, and acanthosis, and proliferation of veins extending deep into the dermis and subcutaneous tissue, although deeper subcutaneous variants may lack the characteristic epidermal changes.1, 2, 3, 4 VVM harbors a somatic missense mutation in mitogen-activated protein kinase kinase kinase 3 (MAP3K3) that leads to malformed dermal venule-like channels.4