Endolymphatic Sac Tumors

Abstract

Tumors of the endolymphatic sac are rare and can be found in patients with Von Hippel Lindau disease. They most often develop within the intrapetrosal part of the sac but can sometimes be located in the distal part. Their growth is slow and they spread in two directions: laterally toward the external and middle ear and in the direction of the jugular foramen and medially into the ponto-cerebellar angle. The symptoms are usually auditive, with a constant neurosensorial deafness of sudden onset in 50 % of cases and sometimes associated with a tinnitus and dizziness. The varieties with medial extension result in a cerebellopontine angle syndrome. Diagnosis is made by imaging (CT scan and MRI) that reveals a heterogeneous tumor between the lateral sinus and the internal auditory meatus, hypervascularized showing contrast, with cystic zones and associated with bone lysis. Histological examination of a papillary cystadenoma is performed and the differential diagnosis is essentially made with a papillary of the choroïd plexus. They require total surgical excision in order to avoid possible recurrence and can be performed by retrosigmoïd approach, or more ideally, by transpetrosal approach.