Endolymphatic sac tumor of the petrous temporal bone: about a case

Endolymphatic sac tumor is a rare, low-grade, locally very aggressive neuroectodermic tumor arising in the inner ear, without metastatic potential. We here report the case of a 60-year old patient presenting with symptoms suggesting damage to the inner ear and other symptoms suggesting damage to the cerebellopontine angle. MRI showed lesion process extending through the mastoid and the temporal bone. The diagnosis of sporadic endolymphatic sac tumor was confirmed by anatomo-pathological examination while the histological type was determined by immunohistochemical study. Endolymphatic sac tumor can occur at any age with an average age at diagnosis of sporadic tumor type of 52 years. It is grouped into 2 major histologic types: papillary and follicular. It is essential to eliminate other differential diagnoses, especially metastases from thyroid carcinoma. Surgical resection may be difficult due to tumor vascularization and its extension through the bones and the meninges. Complete excision provides the best tumour control, preventing recurrence.