Endolymphatic sac tumour. A case report

We present the case of a patient with an endolymphatic sac tumour (ELST). This rare tumour entity has only recently been defined and despite a well characterized clinical appearance misdiagnosis as jugular paraganglioma is frequent. A 68-year-old woman was admitted to our Neurosurgical Department with a mass lesion extending from the left temporal bone to the cerebello-pontine angle (CPA). Radiological features were high vascularization, contrast enhancement and destruction of the os petrosum. After preoperative angiographic embolization the tumour was removed in two surgical interventions, first via a lateral suboccipital approach and second by petrosectomy. The lesion proved to be a typical endolymphatic sac tumour by a synopsis of histological, radiological and clinical features. ELST should be taken into consideration in patients with mass lesions in the cerebellopontine angle destroying the petrous bone and resembling paraganglioma. Since slow growth rate and lack of metastases are particular features of ELST, complete resection of the tumour results in long survival times without adjuvant chemo- or radiotherapy.