Endolymphatic sac tumors. A source of morbid hearing loss in von Hippel-Lindau disease
T. J. Manski, D. K. Heffner, G. M. Glenn, N. J. Patronas, A. T. Pikus, D. Katz, R. Lebovics, K. Sledjeski, P. L. Choyke, B. Zbar, W. M. Linehan and E. H. Oldfield
Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1414, USA.
OBJECTIVES: Isolated reports suggest a possible association of
endolymphatic sac tumors (ELSTs), which are extremely rare in the general
population, with von Hippel-Lindau disease (VHL). To determine if hearing
loss and ELSTs are a component of VHL, we examined prevalence, clinical
presentation, and natural history of hearing loss and ELSTs in VHL. DESIGN:
Brain magnetic resonance images (MRIs) from 374 patients screened for VHL
were reviewed for evidence of ELSTs. The VHL patients with MRI evidence
suggestive of ELSTs or a history of hearing loss, tinnitus, or vertigo
underwent additional radiologic and audiologic evaluations. To further
assess prevalence of hearing loss and ELST in VHL, the next 66 patients
screened in the VHL clinic (49 with proven VHL, 17 at risk for VHL)
received MRI and audiologic assessment. SETTING: Referral center.
PARTICIPANTS: Study subjects comprised 374 persons screened for VHL, 66
consecutive patients with VHL or at risk for VHL, 4 patients with 6 ELSTs,
and 13 previously reported patients with VHL and invasive tumors of the
temporal bone. INTERVENTION: Magnetic resonance image and computed
tomographic (CT) scan of the posterior fossa and audiologic assessment.
MAIN OUTCOME MEASURES: Any ELST visible on MRI or CT and hearing loss
compatible with ELST. RESULTS: Magnetic resonance imaging revealed evidence
of 15 ELSTs in 13 (11%) of 121 patients with VHL, but in none of the 253
patients without evidence of VHL (P<.001). Clinical findings in these 13
patients included hearing loss (13), tinnitus (12), vertigo (8), and facial
paresis (1). Mean age at onset of hearing loss was 22 years (range, 12-50
years). Hearing for pure tones was abnormal in all affected ears and in 6
of the 11 additional, allegedly unaffected ears. In 8 patients (62%),
hearing loss was the first manifestation of VHL. Presence or absence of
hearing loss was associated with duration of symptoms (P<.002) and with
tumor size (P<.01). Further, 43 (65%) of the 66 patients from the VHL
clinic had pure tone threshold abnormalities, abnormalities that occurred
bilaterally in 23 (54%) of the 43 affected subjects; however, evidence is
lacking for a definitive association with ELST (3 [6%] of 49 patients with
proven VHL had ELST evident on MRI). CONCLUSIONS: Hearing loss and ELSTs
are frequently associated with VHL syndrome and should be considered when
screening individuals at risk for VHL and when monitoring patients with an
established diagnosis of VHL. Many patients with VHL have hearing loss
without radiographic evidence of an ELST. Whether it is caused by an ELST
that is too small to be detected by MRI or is produced by some other
etiology is still unknown. Audiologic evaluation and MRI should allow early
detection and enhance management of hearing loss in these patients.
