Elastosis perforans serpiginosa – low magnification

LEGEND

  • Hyperkeratotic crust with transepidermal elimination of elastic fibers

  • Invagination of the epidermis with hyperplasia. The epidermis engulfs or pinches the dermis at the site of perforation (crab claw–like shape).

Elastosis perforans serpiginosa – high magnification

LEGEND

Infiltrate of macrophages, multinucleated giant cells, lymphocytes, or neutrophils at the site of perforation in the dermis

  • Presence of twisted, eosinophilic elastin fragmented into small pieces in the superficial dermis

  • Sometimes, elastophagocytosis is observed, meaning that elastin is phagocytosed by macrophages.

Elastosis perforans serpiginosa

Verhoeff-Van Gieson stain is positive and stains elastic fibers black.