Disclosures

Endolymphatic Sac Tumors and • Scientific advisory board – Roche Pharmaceuticals, Applied Genetic Technologies Corporation von Hippel-Lindau Disease • Investigator – Multi-institutional 5 year study of clinical outcomes of the Cochlear Nucleus Hybrid L24 device Samuel Gubbels, M.D. • Grant funding – NIH/NIDCD Associate Professor, Neurotology • Grant funding – Med El Corporation Director, UCHealth Hearing and Balance Clinics Department of Otolaryngology University of Colorado Denver, CO, USA

Where is the Endolymphatic Sac Outline (ELS)? • Anatomy of ELS • Along the dural lining of • Definition and epidemiology the brain • Back portion of the • Symptoms skull – posterior fossa • Evaluation and treatment • <1 cm triangular shape • Adjunctive measures • Flat • Questions • Fibrous in quality

https://www.semanticscholar.org/paper/Tumors-of-the- endolymphatic-sac-in-von-disease.-Lonser- Kim/978cfd5f3a0d7bee1649eeab6f65c6b70d9a66b7/figure/0

1 What is an Endolymphatic Sac What does the ELS do? Tu m o r ? • Part of the inner ear • Rare tumor membranous system • Slow growing • Endolymph homeostasis • Locally erosive • Removes waste • Endocrine/paracrine • Low grade • Meniere’s disease • Vascular – red/brown – Vertigo attacks • Type of adenocarcinoma – Hearing loss, ringing, ear • fullness Metastases are rare

https://www.gaes.es/viviendoelsonido/foros/post/1939/sindrome-de-la- meniere-y-serc Mendenhall et al.(2018) Advances in Therapy:35:887-898 Lonser et al. (2004) NEJM

History of ELST Epidemiology

• Heffner (1989) – 20 cases • 300 reported cases • vHL – “probable” endolymphatic sac origin • No reported metastases – pVHL tumor suppressor – Female 2:1 ELST • Li (1993) – Reclassified as “ELST” – 1 spinal “drop” metastasis • No gender predilection – 12-50 years old • Magerian (1995) – found 8 cases of ELST in – 30 year old average • 15-77 years old cadaveric skull base collection – 6-15% of vHL patients • 40 yo average • Manski (1997) – part of vHL • 30% both sides with ELST – 32% with ELST at initial • World Health Organization (2012) presentation of vHL – Endorsed “Endolymphatic Sac Tumor” officially

Varshney et al. (2017) J. Kidney Cancer and VHL

2 What Symptoms do ELST Cause? What Symptoms do ELST Cause?

• Hearing loss (86-100%) • Hearing loss (86-100%) – Progressive > sudden – Progressive > sudden Meniere’s Meniere’s • Ringing in the ear/tinnitus – (71-89%) Disease • Ringing in the ear/tinnitus – (71-89%) Disease symptoms symptoms • Vertigo/dizziness (47-70%) • Vertigo/dizziness (47-70%) • Ear fullness (37%) • Ear fullness (37%) • Facial weakness (5-33%) • Headache (37%) • Other cranial nerve symptoms (5-25%)

How is an ELST Diagnosed? How is an ELST Diagnosed?

• Audiogram • Audiogram – Inner ear pattern – Inner ear pattern • Sensorineural • Sensorineural – Asymmetric hearing – Asymmetric hearing – Triggers imaging workup – Triggers imaging workup • Imaging – Computed Tomography (CT)

Wick et al. (2018) Oto Clin N. Am. Mendenhall et al. (2018) Adv. Ther

3 How is an ELST Diagnosed? How is an ELST Diagnosed?

• Audiogram • Audiogram – Inner ear pattern – Inner ear pattern • Sensorineural • Sensorineural – Asymmetric hearing – Asymmetric hearing – Triggers imaging workup – Triggers imaging workup • Imaging • Imaging – Computed Tomography – Computed Tomography (CT) (CT) – Magnetic Resonance – Magnetic Resonance Imaging (MRI) Imaging (MRI) – – PET/CT Wick et al. (2018) Oto Clin N. Am. Papadakis et al. (2016) Clin Nuc Med Mendenhall et al. (2018) Adv. Ther

Screening for ELST in vHL? Staging of ELST

Wick et al. (2018) Oto Clin N. Am. Varshney et al. (2017) J. Kidney Cancer and VHL

4 How are ELST’s Treated? Surgical Details

• Surgery as mainstay • Inpatient procedure in general • Complete excision • Length of stay – 2-3 days paramount • Risks • Hearing preservation possible with small – Hearing loss, dizziness tumors – Facial nerve • Embolization possibly – CSF leakage • Variety of surgical – Recurrence approaches – Bleeding – Incisions behind ear in – Infection general

Outcomes after Surgery Additional Treatments

• Small studies • Radiation therapy – multiple types • Control rates – 75-92% at 1-2 years – Poor surgical candidates • Hearing loss common – Recurrences - multifocal • Cranial nerve problems – Recurrence – surgical morbidity unacceptable • Reports • Radiotherapy or addl surgery can be required – Primary – Incomplete excision, recurrence – Adjunctive - incomplete resection • Control rates vary – Possibly better with radiosurgical techniques

5 Rehabilitation Hearing Rehabilitation

• Dizziness –Vestibular therapy • Cochlear implantation sometimes possible • Facial nerve problems • Hearing on other side? – Variety of procedures to help • Status of cochlea, auditory nerve – Rehabilitation can be beneficial depending • Multiple benefits • Hearing loss – Hearing in noise – Generally a complete loss – Localization – Hearing aids not helpful – Route to other side • CROS or Bone anchored hearing aid

Conclusions

• Screening and early detection paramount • Hearing loss most common symtom • Small tumor with better outcomes • Surgery as mainstay of treatment – Complete resection very important • Other treatments may be necessary • Multiple hearing rehabilitation options

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