title: Endodermal cyst of the oculomotor nerve: case report.
abstract: OBJECTIVE
  Endodermal cysts are commonly found in the anterior spinal cord. Reports of intracranial cases are uncommon. We report a case of endodermal cyst located on the left oculomotor nerve.
  
  
  METHODS
  A 16-year-old female experienced diplopia followed by headache. Neurological examinations revealed left oculomotor nerve palsy. Magnetic resonance imaging scans showed a well-defined multilocular cystic mass in the proximity of the left oculomotor nerve at its exit from the midbrain.
  
  
  METHODS
  This patient underwent biopsy and drainage of the cyst. At surgery, the cyst seemed to be intrinsic to the oculomotor nerve and could not be totally resected. Pathological examination confirmed the diagnosis of endodermal cyst.
  
  
  CONCLUSIONS
  Intracranial endodermal cysts are rare, particularly when associated with the cranial nerves. To our knowledge, this is the second case of endodermal cyst located on the oculomotor nerve. A detailed discussion and review of these case reports are presented.
authors.affiliation: Department of Neurosurgery, Nagasaki University School of Medicine, Nagasaki, Japan. okunaga-nsu@umin.ac.jp
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Okunaga
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tsutsumi
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Izumi
authors.initials: I
authors.lastname: Nagata
mesh_terms: D000293:Adolescent; D003560:Cysts / Q000175:diagnosis* / Q000601:surgery*; D005260:Female; D006801:Humans; D015840:Oculomotor Nerve Diseases / Q000175:diagnosis* / Q000601:surgery*