Linear hyperpigmentation with extensive epidermal apoptosis: a variant of linear lichen planus pigmentosus?

We report 3 female patients who rapidly developed pigmented patches in a linear arrangement. Histologically there was minimum epidermal basal cell damage and bandlike lymphocyte infiltration in the dermis, but focal massive apoptotic materials positively stained with antikeratin antibody were prominently seen in the papillary and subpapillary dermis. We considered these cases as a variant of linear lichen planus pigmentosus with unique histologic change of severe epidermal apoptosis. These histologic features may represent a severe apoptotic change in the end stage of lichenoid tissue reaction.