Case report: endolymphatic sac tumor masquerading as Meniere's disease.

Introduction: Endolymphatic sac tumors are rare, indolent tumors with an initially innocuous presentation of audiovestibular dysfunction mimicking benign, less sinister aetiologies. The objective of this study was to describe the clinical and pathologic features of endolymphatic sac tumors, highlighted by one such case presenting to a tertiary Neuro-otology and Skull Base center. Presentation of case: We report a case of a destructive endolymphatic sac tumor of the middle ear resulting in cranial neuropathies of the facial, vestibulocochlear, and vagus nerves. The acute clinical decline alongside aggressive features of disease seen on skull base imaging prompted urgent surgical exploration for histological diagnosis. Local multidisciplinary collaboration of neuro-otology and skull base surgeons, neuro-radiology, and pathology led to successful diagnosis and initiation of management. Discussion: Retrospectively, the patient had a 10-year history of hearing loss, vertigo, and tinnitus leading to the erroneous diagnosis of Meniere's syndrome. Endolymphatic sac tumors pose a diagnostic challenge owing to their initial innocuous presentation. Differentiating these tumors from other pathologies both radiologically and histologically also poses a challenging - emphasizing the need for multidisciplinary input and tertiary-level management. Conclusions: The lateral skull base surgeon must be cognisant of this rare pathology and of the potential ramifications the diagnosis may have due the association of endolymphatic sac tumors with von Hippel-Lindau syndrome.