Idiopathic midline destructive disease: fact or fiction.

The differential diagnosis of a progressive destructive lesion of the midface and upper airway region includes both neoplastic and non-neoplastic entities; of these, the majority of cases prove to be either Wegener's granulomatosis or lymphoma. Historically, these sorts of necrotizing midfacial lesions were diagnosed clinically, and as a consequence a variety of overlapping categories of disease sprang up. As pathologic examination of biopsy material became both more widespread and (particularly in the last several years) more sophisticated, many lesions previously thought to be of mysterious origins have proven to be examples of lymphoma (in particular, sinonasal natural killer cell or T cell [NK/T] lymphomas). At present, the evaluation of a patient with a progressive destructive process involving the midface region should include imaging studies (to delineate the extent of disease) as well as biopsy (with sampling of lesional tissue for application of sophisticated testing--including immunohistochemical studies, flow cytometry, or molecular studies as necessary--to exclude the possibility of a NK/T cell lymphoma). There remain occasional patients whose necrotizing midfacial lesions continue to be difficult to classify despite the application of extensive testing; such patients are sometimes described as suffering from the nebulous entity of "idiopathic midline destructive disease". While it remains to be seen whether such patients will ultimately be assigned to other diagnostic groups (as, for example, occult toxic injuries--as in the case of cocaine abusers who are not forthcoming with regard to their drug usage), it seems likely that "idiopathic midline destructive disease" is a diagnostic term of questionable validity which should be used only with extreme reticence in modern practice.