NCT00001668 2008-03-04Endolymphatic Sac Tumors in a Population of Patients With Von Hippel-Lindau Disease:The Natural History and Pathobiology, and a Prospective Non-Randomized Clinical Trial of Hearing Preservation Surgery in Patients With Early Stage Endolymphatic Sac TumorsNational Institutes of Health Clinical Center (CC)Completed75 enrolled