Endolymphatic sac papillary tumor (endolymphatic sac adenoma, temporal-mastoid bone adenoma or adenocarcinoma, low-grade adenocarcinoma of potential endolymphatic sac origin, aggressive papillary tumor of the temporal bone, Heffner's tumor) is a rare lesion that involves the temporal bone. This tumor usually appears alone, but in 11-30% of afflicted individuals, it is accompanied by von Hippel-Lindau disease. Endolymphatic sac papillary tumors are destructive tumors that exhibit locally aggressive behavior. They slowly grow into the posteromedial section of petrous temporal bone. The main symptoms produced by these lesions include hearing loss and cranial nerve deficits. Endolymphatic sac papillary tumors develop in two principal patterns that histopathologically form follicular and papillary or solid structures. Those two patterns are usually manifested in the same tumor. Immunochemical analysis of these tumors usually reveals cytokeratin, vimentin, epithelial membrane antigen, and (less frequently) S-100 protein and neuron-specific enolase. Local excision is curative for endolymphatic sac papillary tumors. The currently favored method of treatment consists of excision and long-term follow-up. The role of adjuvant radiotherapy as treatment is controversial. This case report describes an endolymphatic sac tumor in a 22-year-old woman without von Hippel-Lindau disease who had a number of complaints, including deafness in her left ear, complete left-sided facial paralysis, and hoarseness of approximately 8 years' duration. (C) 2007 Elsevier Ireland Ltd. All rights reserved.