Endocrine Abstracts

Introduction: Endolymphatic sac tumors (ELSTs) are very rare and locally aggressive low-grade neoplasm of endolymphatic system origin, which can arise sporadically or in association with von Hippel–Lindau (VHL) disease. It is an autosomal dominant multisystem disorder with a prevalence of 1 in 39 000 people that predisposes the patients to clear cell neoplasms of various organs. Herein, we report a rare case of an ELST in a patient with VHL disease, in order to describe the clinicopathologic features of the case.

Case presentation: A female, 58-year-old patient was referred to our Otolaryngology Department with one-year history of progressive sensorineural hearing loss in the left ear and non-pulsatile tinnitus. The family medical history disclosed the presence of symptoms of von Hippel–Lindau disease. Her mother, brother and three nephews had history of resection of cerebellar hemangioblastomas and evidence of genetic VHL disease. A complete otorhinolaryngological examination was performed and it was normal. Pure tone audiometry showed left side mild sensorineural hearing loss. Computed tomography (CT) scan done primary without contrast then injected in second time showed a low-density lesion with enhancement on contrast arising from the left side of the cerebellopontine angle region. Erosion of the left petrosal bone and mastoid air cells was observed, extending to the internal auditory meatus. On magnetic resonance imaging (MRI) study, a 3.2×1.8×2.6 cm hyper vascular lesion was detected in the petrous part of the left temporal bone and mastoid air cells. Moreover, a work-up was performed to confirm the VHL syndrome. An ophthalmologic examination done detected multiple hemangioblastomas of the retina and an ultrasonography of the abdomen revealed bilateral renal cysts. Genetic study was not performed on our case. With these findings a provisional diagnosis of ELST associated with VHL disease was made. Therefore, the patient was treated with intensity modulated radiotherapy. She is followed regularly for 36 months with routine MRI surveillance. There were no several complaints and MRI display no radiological signs of progression.

Discussion & Conclusion: Endolymphatic sac tumors are rare neoplasm of the petrous temporal bone that has a slight female predominance. The association between ELST and VHL disease has increased our knowledge of this rare tumor. Approximately 10% of patients with VHL disease have ELSTs. Early surgery resection is the best treatment strategy of this tumour and radiotherapy is used almost exclusively as palliative treatments for tumors that cannot be resected completely.