title: Endolymphatic sac tumors: clinical outcome and management in a series of 9 cases.
abstract: OBJECTIVE
  Endolymphatic sac tumors (ELSTs) are rare adenomatous tumors arising in the petrous bone, either spontaneously (isolated) or in association with von Hippel-Lindau (VHL) disease. For 9 patients, this study describes the typical features and management of ELST and the clinical outcome of treatment. Similarities and differences are identified for ELST in isolation and in association with VHL disease.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  The patient database was searched for patients diagnosed with ELST. All other tertiary referral centers in The Netherlands were invited to do likewise.
  
  
  METHODS
  The patient records were screened for presenting symptoms, hearing, imaging, treatment, and treatment outcome. Histopathologic finding was reviewed by a senior pathologist.
  
  
  RESULTS
  Six patients with an isolated ELST and 3 patients with an ELST in association with VHL disease were identified. In the isolated ELST group, 5 patients were treated surgically and 1 patient was administered primary radiotherapy. In the VHL group, 1 patient underwent surgery and 2 patients were treated conservatively after a wait-and-magnetic resonance imaging-scan protocol. All individual treatment outcomes are scrupulously presented in this article.
  
  
  CONCLUSIONS
  This study compiles and describes 9 cases of ELST. In 8 of 9 patients, the ELST could be controlled by surgery, radiotherapy, or a wait-and-scan protocol. The large interpatient differences make it difficult to standardize the management of this disease. The management is strongly influenced by comorbidity and tumor stage.
authors: Department of Otorhinolaryngology, Head and Neck Surgery, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. f.timmer@kno.umcn.nl
authors: Ferdinand C A
authors: FC
authors: Timmer
authors: Luud J
authors: LJ
authors: Neeskens
authors: Lund J
authors: LJ
authors: Neeskens
authors: Frank J A
authors: FJ
authors: van den Hoogen
authors: Frank J A
authors: FJ
authors: van de Hoogen
authors: Pieter J
authors: PJ
authors: Slootweg
authors: Erwin A
authors: EA
authors: Dunnebier
authors: Bernard K H
authors: BK
authors: Pauw
authors: Bernard H
authors: BH
authors: Pauw
authors: Jef J S
authors: JJ
authors: Mulder
authors: Cor W R J
authors: CW
authors: Cremers
authors: Henricus P M
authors: HP
authors: Kunst
authors: Dirk P M
authors: DP
authors: Kunst
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D000328:Adult; D000368:Aged; D004428:Ear Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D004712:Endolymphatic Sac / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome