title: Peripetrosal arachnoid cysts.
abstract: OBJECTIVE
  The present review summarizes the current theories on arachnoid cyst formation, the common presentations of cysts surrounding or eroding the temporal bone from the middle and posterior cranial fossae, the diagnostic strategies and the management considerations and options.
  
  
  RESULTS
  Arachnoid cysts are most common in the middle cranial fossa and rarely present in association with the petrous apex. They are frequently found incidentally on imaging studies performed in the workup for unrelated symptoms. When they do cause symptoms, these are usually nonspecific. Thus it is important to establish the relationship between the two. Peripetrosal arachnoid cysts may cause cranial nerve deficits in addition to symptoms related to intracranial hypertension. Small asymptomatic cysts are managed conservatively with serial imaging. Large symptomatic cysts are often managed surgically with shunting, open excision or open or neuroendoscopic fenestration or marsupialization. The management of large asymptomatic cysts depends on the patient and cyst characteristics.
  
  
  CONCLUSIONS
  Peripetrosal arachnoid cysts are often incidental findings. Careful selection of surgical candidates is of utmost importance. Multiple surgical options with similar success rates are available. The rates and profile of their complications may differ. Overall, approximately 70% of patients experience improvement in their symptoms with surgery.
authors.affiliation: Otology, Neurotology, and Skull Base Surgery, Bobby R. Alford Department of Otolaryngology - Head and Neck Surgery, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Cristobal
authors.forename: John S
authors.initials: JS
authors.lastname: Oghalai
mesh_terms: D016080:Arachnoid Cysts / Q000175:diagnosis* / Q000628:therapy*; D003952:Diagnostic Imaging; D006801:Humans; D019635:Neurosurgical Procedures; D013517:Otorhinolaryngologic Surgical Procedures