Disseminated Superficial Porokeratosis with Dermal Amyloid Deposits.

Only 6 cases with an association of disseminated superficial porokeratosis with dermal amyloid deposits are reported in the literature. We present the case of a 76-year-old woman who presented with a disseminated superficial porokeratosis. Histological examination revealed amyloid deposits in the upper dermis, which were typed with routine HE stains, Congo red stains and anticytokeratin antibodies (AE1-AE3 and CK5). Positive staining with Congo red and, moreover, with CK5 (a cytokeratin strongly represented in the basal cell layer of the epidermis) indicates an epidermal origin of this protein.