Midfacial necrotizing diseases.

Wegener's granulomatosis, a systemic disorder, manifests specific clinical and histopathologic findings that allow it to be separated from an unrelated group of upper airway lesions. Two of these, non-Hodgkin's lymphoma and polymorphic reticulosis, are related and may in fact be variable expressions of a lymphoma. A fourth, and fortunately rare, disorder presents as a severely destructive localized lesion without any specific histopathologic findings.