Fume-induced fluorescence in diagnosis of nasal neuroblastoma.

Nasal neuroblastoma, esthesioneuroblastoma, is frequently difficult to distinguish from the more common poorly differentiated epidermoid carcinoma of the nasal cavity and nasopharynx. We present a simple alternate method to electron microscopy, formaldehyde-fume-induced fluorescence, to demonstrate biogenic amine granules in neoplastic cells. This method is more specific and more sensitive, since it reveals the presence of biogenic amines, not merely membrane-bound granules, and it deals with larger quantities of tissue, thus avoiding some of the sampling errors inherent in electron microscopy. We also describe the histochemical relationship of this tumor to other neural crest neoplasms.