title: Ovarian teratoma development after anti-NMDA receptor encephalitis treatment.
abstract: BACKGROUND
  Anti-NMDA-R receptor encephalitis occurs predominantly in younger women and is often comorbid with ovarian teratoma, a feature that is often absent in children. Here, we report our experience with two pediatric patients, in whom no tumors were present during treatment for encephalitis, but in whom ovarian teratomas developed without encephalitis relapse after treatment was completed.
  
  
  METHODS
  Patient 1 was a 14-year-old girl who was diagnosed due to characteristic symptoms and anti-NMDA-R antibody. MRI scanning during treatment revealed no ovarian tumors, but a tumor developed in the right ovary 10months after onset. Another tumor developed in the left ovary 3years after onset, and a mature ovarian teratoma was confirmed after bilateral partial ovariectomy. Patient 2 was an 11-year old girl who was also diagnosed due to characteristic symptoms and anti-NMDA-R antibody. Imaging during treatment revealed no ovarian tumors, but a 2.5-cm tumor mass was found in the left ovary 10months after onset, and a mature ovarian teratoma was confirmed after partial ovariectomy.
  
  
  CONCLUSIONS
  This case report suggests the need for regular tumor screening after treatment for anti-NMDA receptor encephalitis because of potential subsequent tumor development, even in pediatric patients who initially present with no comorbid tumors. No analysis of relapse risk has yet been reported in cases of tumor development after treatment, and at this point, whether or not resection is needed to prevent relapse remains unclear. However, because teratomas usually grow, have an associated risk of torsion, and can be malignant, tumor removal should be considered.
authors.affiliation: Division of Child Neurology, Chiba Children's Hospital, Chiba, Japan. Electronic address: takuoma@hotmail.co.jp.
authors.forename: Taku
authors.initials: T
authors.lastname: Omata
authors.affiliation: Division of Child Neurology, Chiba Children's Hospital, Chiba, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kodama
authors.affiliation: Division of Child Neurology, Chiba Children's Hospital, Chiba, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Division of Child Neurology, Chiba Children's Hospital, Chiba, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Iida
authors.affiliation: Department of Obstetrics, Kameda Medical Center, Kamogawa, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Furusawa
authors.affiliation: Department of Obstetrics, Sakura Hospital Medical Center, Toho University, Sakura, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Takashima
authors.affiliation: Department of Pediatrics, Shizuoka Institute of Epilepsy and Neurological Disorders, NHO, Shizuoka, Japan.
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Molecular Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakuma
authors.affiliation: Department of Neurology, Kanazawa Medical University, Kanazawa, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Pediatrics, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Fujii
authors.affiliation: Department of Pediatrics, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Shimojo
mesh_terms: D000293:Adolescent; D060426:Anti-N-Methyl-D-Aspartate Receptor Encephalitis / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D010051:Ovarian Neoplasms / Q000209:etiology*; D013724:Teratoma / Q000209:etiology*
keywords: Anti-NMDA receptor encephalitis; Children; Ovarian teratoma; Treatment