Endolymphatic sac tumor - A rare differential diagnosis in cerebellopontine angle lesions

Abstract

Endolymphatic sac tumors (ELSTs) extending to the cerebellopontine angle (CPA) are extremely rare and generally misdiagnosed as meningioma or neurinoma. Recognition of such a tumor is of paramount importance, because preoperative strategies may help the surgeon to excise the tumor completely. A case of a CPA tumor that was diagnosed radiologically as meningioma or neurinoma before surgery is reported here. Histopathologically, however, the lesion proved to be an ELST. Any lesion with an unusual appearance on magnetic resonance imaging in the CPA may be an ELST, and the diagnosis should be considered in the differential diagnosis.