Disseminated superficial porokeratosis with dermal amyloid deposits: case report and immunohistochemical study of amyloid.

The association of porokeratosis with dermal amyloid deposits is extremely rare, only three cases are reported in the literature. We describe a case of disseminated superficial porokeratosis (DSP) with clear histologic evidence of amyloid deposition in the upper dermis. The amyloid was typed with an original immunohistochemical assay based on three anticytokeratin antibodies (MNF 116, CK1, KER B). The epidermal origin of the substance (K amyloid) was demonstrated by its strong positivity for MNF 116 and KER B.