The midline granuloma syndrome.

We propose that the term midline granuloma be used to designate a syndrome and not specific forms of disease. We present a classification and terminology that divides the entities previously grouped under "midline granuloma" into four main categories: Wegener's granulomatosis, idiopathic midline destructive disease, lymphomatoid granulomatosis, and angiocentric lymphoma. Except in the case of idiopathic midline destructive disease, which is exclusively limited to the upper respiratory tract, the other forms can be localized or disseminated. In most cases the histopathologic distinction between these forms can be reliably made and provides guidance for therapy.