Cutaneous lymphoma masquerading as granuloma faciale.

Granuloma faciale is a presumably benign disorder of the skin--usually of the face--characterized by a dense, polymorphous, inflammatory infiltrate including numerous eosinophils, separated from the epidermis by a clear or "grenz" zone, and possessing a small vessel, leukocytoclastic vasculitis. Primary malignant lymphoma of the skin, other than mycosis fungoides, is an unusual entity that may follow a widely variable course and is often extremely difficult to diagnose definitively. A patient is presented in whom a lesion consistent with granuloma faciale changed its histological appearance and clinical behavior into that of a malignant lymphoma.