title: An unusual presentation of a lumbar synovial cyst: case report.
abstract: METHODS
  A case of intraforaminal synovial cyst is reported.
  
  
  OBJECTIVE
  To stress the importance of the way intraforaminal synovial cyst, a very rare condition, causes a peculiar position of the nerve root in the foramen and to describe the required surgical approach.
  
  
  BACKGROUND
  Intraforaminal synovial cyst is a highly unusual finding. The existence of this rare entity raises the problem of differential diagnosis with other space-occupying lesions of the neural foramen, such as herniated disc, neurinoma, neurofibroma, and metastatic lesions
  
  
  RESULTS
  A 64-year-old woman suffered a right L4 radiculopathy with motor deficit. Computed tomography showed a space-occupying lesion in the L4-L5 foramen isodense with the disc. Magnetic resonance images showed a right intraforaminal cystic lesion at the L4-L5 level with no enhancement after intravenous infusion of gadolinium. A 3-cm cystic lesion, which appeared to arise from the L4-L5 facet joint without direct communication, was excised from the L4-L5 foramen. In contrast with intraforaminal disc herniation, downward displacement of the L4 nerve root was observed. Two months after surgery, the patient was pain-free and neurologic examination revealed no motor deficit.
  
  
  CONCLUSIONS
  An unusual intraforaminal presentation of a lumbar synovial cyst demonstrates the importance of considering this entity and of adapting the surgical technique to avoid injury to the nerve root.
authors.affiliation: Department of Neurosurgery and Neuropathology, Hopital Timone, Marseille, France. p.metellus@infonie.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Métellus
authors.forename: Stéphane
authors.initials: S
authors.lastname: Fuentes
authors.forename: Henry
authors.initials: H
authors.lastname: Dufour
authors.forename: Laurent
authors.initials: L
authors.lastname: Do
authors.forename: Danièle
authors.initials: D
authors.lastname: Figarella-Branger
authors.forename: François
authors.initials: F
authors.lastname: Grisoli
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D005682:Gadolinium; D006801:Humans; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011843:Radiculopathy / Q000209:etiology; D013581:Synovial Cyst / Q000150:complications / Q000175:diagnosis* / Q000601:surgery
chemical_list: D005682:Gadolinium