Patients meeting the diagnostic criteria for von Hippel-Lindau (VHL) disease.

No persons who are pregnant or lactating are eligible for the surgical arm of this protocol until the pregnancy and/or nursing period has reached completion.

No patients with disorders associated with multiple abnormalities of the middle ear and inner ear. Specific laboratory abnormalities such as anti-HIV-1, FTA-Abs, serum ANA, and ANCA have been associated with AIDS, Syphilis, Systemic Lupus Erythematosus, and Wegener's Granulomatosis, respectively.

No patients currently undergoing chemotherapeutic regimen with ototoxic agents (e.g., cisplatin). Other agents will be reviewed on a case-by-case basis for their potential to cause ototoxicity and thereby interfere with audiologic data interpretation.

Patients with an ELST in an only hearing ear will be excluded from the protocol for surgical treatment of ELST's (except in cases where other medical indications necessitate intervention for the welfare of the patient).

Patients with only unilateral vestibular function on the side affected by the ELST, as documented by caloric ENG testing, will be excluded from the surgical treatment group in most cases.

No patients with the inability to understand all of the requirements of the study or inability to give informed consent and/or comply with all aspects of the evaluation.