Isolated focal non-epidermolytic palmoplantar keratoderma

A rare hereditary palmoplantar keratoderma characterized by focal hyperkeratotic lesions on the palms and soles. Histopathologic examination reveals prominent hyperkeratosis, thickened stratum spinosum with reduced stratum granulosum, disadhesion of cells in the suprabasal layers, elongation of rete ridges, and sparse lymphocyte infiltration in the dermis.