Hyperkeratosis - Thickened stratum corneum

Hyperkeratosis or thickened stratum corneum is a feature of the palms and soles. There is no associated inflammatory changes.      Virtual Slide

Hyperkeratosis can be layered orthokeratosis or layered parakeratosis. The latter is seen in hyper proliferative conditions such as some of the red scaly diseases and solar keratoses.   Virtual Slide

Hyperkeratosis with cornoid lamellae is a feature of porokeratoses.     Virtual Slide

Hyperkeratosis with gram positive bacteria on the surface is seen in Pitted keratolysis a Corneybacterial infection.   Virtual Slide

Epidermolytic hyperkeratosis is a distinctive change in the granular layer with intracytoplasmic vacuolization of the stratum granulosum and upper stratum spinosum giving a reticulated appearance with overlying hyperkeratosis. It is seen in acrodermatitis enteropathica and other deficiency diseases such as pellagra and necrolytic migratory erythema but also in some epidermal nevi, Bullous congenital ichthyosiform erythroderma, some isolated and disseminated epidermolytic acanthomas , some warts and a variant of keratoderma.