title: Anti-N-methyl-D-aspartate receptor encephalitis with an imaging-invisible ovarian teratoma: a case report.
abstract: BACKGROUND
  Anti-N-methyl-D-aspartate receptor encephalitis is a recently discovered disease entity of paraneoplastic limbic encephalitis. It largely affects young women and is often associated with an ovarian teratoma. It is a serious yet treatable condition if diagnosed early. Its remedy involves immunotherapy and surgical removal of the teratoma of the ovaries. This case of anti-N-methyl-D-aspartate receptor encephalitis involves an early surgical intervention with bilateral oophorectomy, despite negative imaging evidence of a teratoma.
  
  
  METHODS
  A 25-year-old white woman with anti-N-methyl-D-aspartate receptor encephalitis presented with behavioral changes and seizures that were confirmed to be secondary to anti-N-methyl-D-aspartate receptor encephalitis. She required an admission to our intensive care unit for ventilator support and received a number of immunological therapies. Multiple imaging investigations showed no evidence of an ovarian teratoma; she had a bilateral oophorectomy 29 days after admission. Ovarian histology confirmed the presence of a teratoma with neuronal cells. A few days after the operation she began to show signs of improvement and, apart from mild short-term memory loss, she returned to normal function.
  
  
  CONCLUSIONS
  Our patient is an example of teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis, in which the teratoma was identified only microscopically. Her case highlights that even with negative imaging evidence of a teratoma, ovarian pathology should still be considered and explored.
authors: Department of Medicine, Joondalup Health Campus, Joondalup, Western Australia, Australia.|Academy of Neurology, Joondalup Health Campus, Joondalup, Western Australia, Australia.|Neurodegenerative Disorders Research Pty Ltd, 4 Lawrence Avenue, West Perth, Western Australia, 6005, Australia.
authors: Zainab M
authors: ZM
authors: Abdul-Rahman
authors: Department of Medicine, Joondalup Health Campus, Joondalup, Western Australia, Australia. research@ndr.org.au.|Academy of Neurology, Joondalup Health Campus, Joondalup, Western Australia, Australia. research@ndr.org.au.|Neurodegenerative Disorders Research Pty Ltd, 4 Lawrence Avenue, West Perth, Western Australia, 6005, Australia. research@ndr.org.au.|Department of Medicine, The University of Western Australia, Perth, Western Australia, Australia. research@ndr.org.au.
authors: Peter K
authors: PK
authors: Panegyres
authors: Ramsay Health, Joondalup Health Campus, Joondalup, Western Australia, Australia.
authors: Margareta
authors: M
authors: Roeck
authors: Ramsay Health, Joondalup Health Campus, Joondalup, Western Australia, Australia.
authors: David
authors: D
authors: Hawkins
authors: Ramsay Health, Joondalup Health Campus, Joondalup, Western Australia, Australia.
authors: Jude
authors: J
authors: Bharath
authors: Ramsay Health, Joondalup Health Campus, Joondalup, Western Australia, Australia.
authors: Paul
authors: P
authors: Grolman
authors: Ramsay Health, Joondalup Health Campus, Joondalup, Western Australia, Australia.
authors: Cliffe
authors: C
authors: Neppe
authors: Western Diagnostic Pathology, Joondalup Health Campus, Joondalup, Western Australia, Australia.
authors: David
authors: D
authors: Palmer
mesh_terms: D000328:Adult; D060426:Anti-N-Methyl-D-Aspartate Receptor Encephalitis / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007167:Immunotherapy; D001523:Mental Disorders / Q000209:etiology; D010051:Ovarian Neoplasms / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D010052:Ovariectomy; D012121:Respiration, Artificial; D012640:Seizures / Q000209:etiology; D013724:Teratoma / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D016896:Treatment Outcome
keywords: Case report; Encephalitis; NMDA receptor; Oophorectomy; Paraneoplastic; Teratoma