Primary sphenoid sinus esthesioneuroblastoma.

Esthesioneuroblastoma is a rare malignant tumor of undifferentiated neuroectodermal origin. Because these tumors are derived from olfactory epithelium, most cases arise in the superior nasal cavity at the level of the cribriform niche. The development of an esthesioneuroblastoma outside of the region in which olfactory epithelium exists is exceedingly rare. We report a rare case of a primary sphenoid sinus esthesioneuroblastoma and discuss the pathogenesis, clinical presentation, and treatment of this rare entity.