A case of acral melanocytic hyperplasia: a unique pigmented lesion mimicking acral lentiginous melanoma in situ.

A mottled black pigmented patch on the sole of the foot is reported. Clinically, the lesion closely mimicked acral lentiginous melanoma in situ. However, the histologic findings revealed melanocytic hyperplasia with minimal cytologic atypia confined to the epidermis. Irregular pigmented patches in the acral region comprise a heterogenous group of lesions that range from benign melanocytic hyperplasia to acral lentiginous melanoma.