Granuloma faciale. Ultrastructural study of three cases.

Light and electron microscopic observations were carried out in three cases of granuloma faciale. The dense granulomatous infiltrate of the corium showed: 1) more eosinophils than suspected by light microscopy, most of them with degenerative changes; 2) Charcot-Leyden chrystals; 3) numerous large histiocytes with their cytoplasms filled with lysosomal vesicles containing various inclusions (lamellar figures, myelin bodies, circular concentric organelles, digested membrane structures). The lack of Langerhans granules in dermal cells seems a valid reason to differentiate granuloma faciale from eosinophilic granuloma of the skin, usually considered a variety of histiocytosis X. No evidence of bacterial or viral infections was noticed. Granuloma faciale, despite its uncertain etiology, seems to represent a true entity.