title: Multiple extradural arachnoid cysts: report of two operated cousin cases.
abstract: METHODS
  Report of 2 operated cousin cases of the multiple spinal extradural arachnoid cysts.
  
  
  OBJECTIVE
  To report the operative findings of cousin cases of the multiple spinal extradural arachnoid cysts and analyze a genetic etiology with the pedigree of all family members.
  
  
  BACKGROUND
  Spinal extradural arachnoid cyst is a relatively rare condition that occupies the intraspinal space and sometimes causes neurologic disturbances. The exact etiology is unknown since most reported cases are sporadic. Minimally invasive treatments have been recently applied to a single extradural arachnoid cyst. However, it is still unknown which minimally invasive treatments can be applied to the multiple extradural arachnoid cysts.
  
  
  METHODS
  We experienced 2 cousin cases of multiple spinal extradural arachnoid cysts. Operative findings were described. The pedigree of all family members was made, and a genetic etiology was discussed.
  
  
  RESULTS
  Minimally invasive treatment was tried in Case 1. However, it failed to remove all cysts completely. Each cyst had each stalk communicating with subarachnoid space in both cases. Pedigree showed that the mode of inheritance was likely autosomal dominant.
  
  
  CONCLUSIONS
  When the cysts are multiple, it is necessary to identify a dural defect in each cyst. The etiology of the multiple extradural arachnoid cysts may be hereditary.
authors.affiliation: Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, Fukushima City, Fukushima, Japan. yabuki@fmu.ac.jp
authors.forename: Shoji
authors.initials: S
authors.lastname: Yabuki
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kikuchi
mesh_terms: D000293:Adolescent; D016080:Arachnoid Cysts / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D002648:Child; D004824:Epidural Space / Q000473:pathology; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007796:Laminectomy; D019028:Magnetic Resonance Imaging, Cine; D019060:Minimally Invasive Surgical Procedures; D010375:Pedigree; D012307:Risk Factors; D013346:Subarachnoid Space / Q000473:pathology; D013904:Thoracic Vertebrae / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome