A skin biopsy specimen revealed a thinned epidermis and an infiltrate composed of histiocytes and numerous multinucleate giant cells with "ground glass" eosinophilic cytoplasm within the reticular dermis. Histochemical staining demonstrated that the cytoplasm of these giant cells contained a periodic acid–Schiff–reactive and diastase-resistant material. Immunohistochemical staining revealed CD68-positive multinucleate giant cells, suggesting non–Langerhans cell histiocytes. Radiographic examination revealed extensive symmetrical erosive changes.
Red-Brown Papules and Nodules in a 53-Year-Old Woman. Arch Dermatol. 2001;137(9):1241-1246. doi: