Ultrastructural appearances of disseminated superficial actinic porokeratosis.

The ultrastructure of the cornoid lamella and adjacent epidermis was studied by transmission electron microscopy in seven patients with disseminated superficial actinic porokeratosis (DSAP). In the region of the cornoid lamella similar ultrastructural changes were seen in various degrees in all cases. The main changes were seen in various degrees in all cases. The main changes included reduplication of the basal lamina at the dermo-epidermal junction, vacuolar change in the keratinocytes with numerous autophagic vacuoles, glycogen accumulation, dyskeratotic cells, parakeratotic cells containing degraded organelles, and a reduced granular layer.