Examination of hematoxylin-eosin–stained sections from a lesion on the forearm revealed a transepidermal perforating canal and acanthosis of the epidermis on either side of the perforating canal. Eosinophilic filaments were found being extruded from the dermis through the plug. An orcein stain showed a marked increase in elastic tissue in the dermis, as well as elastic fibers intermingled with keratin and cellular debris in the epidermal plug (Figure 5).
A Long-standing Keratotic Papular Eruption. Arch Dermatol. 2000;136(3):417-422. doi: