(84) Ovarian cystectomy to manage teratoma-associated paraneoplastic anti-NMDA-receptor encephalitis: a case report and review of the literature

Background: Anti-NMDA receptor encephalitis is a rare complication of ovarian teratomas. The underlying pathogenesis is likely an antibody-mediated reaction to exposure to ectopic neural tissue. Resection of the ovarian teratoma is considered a component of first line therapy. However, given the rarity of this diagnosis, management with oophorectomy versus cystectomy is not well defined. We present the case of an adolescent diagnosed with anti-NMDA receptor encephalitis who underwent a laparoscopic ovarian cystectomy of a benign teratoma. We review the literature to inform best surgical management.

Case: A 14-year-old presented with new onset neurological symptoms including confusion, hallucinations and generalized tonic-clonic seizures. A comprehensive neurological workup identified NMDA receptor antibodies within the cerebrospinal fluid and MR revealed features of encephalitis. She was started on methylprednisone and plasmapheresis while further work up to identify an underlying neoplastic etiology was completed. Pelvic imaging showed a 0.6 cm ovarian lesion containing fat, concerning for teratoma. She underwent laparoscopic ovarian cystectomy on day 13 of her hospital admission. Pathology confirmed a benign teratoma containing glial tissue. Her neurological symptoms resolved, and she was discharged from hospital to a rehabilitation center approximately 5 weeks later.

Comments: Early resection of the ovarian teratoma improves rates of recovery and reduces disease relapse. However, to our knowledge, data to inform surgical approach in the pediatric and adolescent patient is limited to case reports and series.

Existing literature was reviewed to summarize surgical experience. In total, 49 patients under the age of 18 with a diagnosis of anti-NMDA receptor encephalitis with an ovarian teratoma were identified. Most teratomas were benign (69%). Patient ranged from 7 to 17 years of age. All underwent surgical management: ovarian cystectomy (30%), unilateral salpingoophorectomy (39%), bilateral salpingoophorectomy (2%) and partial oophorectomy (6%). The surgical approach was not specified for 27% of patients. Most patients recovered (94%) with no difference between patients who underwent cystectomy versus oophorectomy (p < 0.05). There is a paucity of long term follow up.

The surgical approach to ovarian teratomas in pediatric and adolescent patients with anti-NMDA receptor encephalitis is variable. Collaborative, prospective efforts are required to inform decision making, with longitudinal data to understand the impact of cystectomy versus oophorectomy on long term outcomes.