ENDOLYMPHATIC SAC TUMORS - A SOURCE OF MORBID HEARING-LOSS IN VON-HIPPEL-LINDAU-DISEASE

Objectives.-Isolated reports suggest a possible association of endolym phatic sac tumors (ELSTs), which are extremely rare in the general pop ulation, with von Hippel-Lindau disease (VHL). To determine if hearing loss and ELSTs are a component of VHL, we examined prevalence, clinic al presentation, and natural history of hearing loss and ELSTs in VHL. Design.-Brain magnetic resonance images (MRIs) from 374 patients scre ened for VHL were reviewed for evidence of ELSTs. The VHL patients wit h MRI evidence suggestive of ELSTs or a history of hearing loss, tinni tus, or vertigo underwent additional radiologic and audiologic evaluat ions. To further assess prevalence of hearing loss and ELST in VHL, th e next 66 patients screened in the VHL clinic (49 with proven VHL, 17 at risk for VHL) received MRI and audiologic assessment, Setting.-Refe rral center. Participants.-Study subjects comprised 374 persons screen ed for VHL, 66 consecutive patients with VHL or at risk for VHL, 4 pat ients with 6 ELSTs, and 13 previously reported patients with VHL and i nvasive tumors of the temporal bone. Intervention.-Magnetic resonance image and computed tomographic (CT) scan of the posterior fossa and au diologic 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 wit h VHL, but in none of the 253 patients without evidence of VHL (P<.001 ), Clinical findings in these 13 patients included hearing toss (13), tinnitus (12), vertigo (8), and facial paresis (1). Mean age al onset of hearing loss was 22 years (range, 12-50 years). Hearing for pure to nes was abnormal in all affected ears and in 6 of the 11 additional, a llegedly unaffected ears. In 8 patients (62%), hearing loss was the fi rst manifestation of VHL. Presence or absence of hearing loss was asso ciated 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 ton e 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 wi th an established diagnosis of VHL. Many patients with VHL have hearin g 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 s ome other etiology is still unknown. Audiologic evaluation and MRI sho uld allow early detection and enhance management of hearing loss in th ese patients.