Sporadic endolymphatic sac tumor--a diagnostic and therapeutic challenge.

Endolymphatic sac tumor (ELST) is a rare low-grade locally aggressive neoplasm of the inner ear that may occur sporadically or in the setting of von Hippel-Lindau syndrome. We herein present a case of sporadic ELST in a 39-year-old man, treated using an interdisciplinary approach (surgery+radiotherapy), with a 10-year follow-up. The patient presented with hearing loss of sudden onset. The treatment of choice for ELST is radical tumor resection, which is associated with a good long-term prognosis. Remission may last for years, but there may be local recurrences, probably as a result of incomplete resection. Adjuvant radiotherapy is an option in case of recurrence and could be discussed after incomplete resection. The purpose of this report is to call attention to ELSTs, which are difficult to diagnose due to their rarity and variety of presentations.