Anti-N-methyl-d-aspartate receptor encephalitis associated with ovarian teratoma: clinical presentation, diagnosis, treatment, and surgical management

Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is a newly recognized autoimmune disorder with prominent neuropsychiatric symptoms, usually part of a paraneoplastic syndrome. We present two cases of patients with anti-NMDA receptor encephalitis related to ovarian teratoma. Our two patients developed neuropsychiatric symptoms and later evolved into a state of impaired consciousness. The physical examinations and investigations, including routine laboratory testing, a basic metabolic panel, MRI of the brain, and the cerebrospinal fluid (CSF) analysis were non-specific. CT scan and MRI of the pelvis revealed a calcified tumor that was suspected to be an ovarian teratoma in both patients. Each patient underwent salpingo-oophorectomy, and histopathological diagnosis of the patient of case 1 was mature cystic teratoma and that of case 2 was immature teratoma. Finally, the result of the anti-NMDA receptor antibody assay demonstrated high antibody titers in CSF, leading to definite diagnosis of anti-NMDA receptor encephalitis triggered by ovarian teratoma in both cases. Given that anti-NMDA receptor encephalitis often results in severe symptoms regardless of the tumor size of the ovarian teratoma, accurate diagnosis of the teratoma followed by prompt surgical resection of the tumor is crucial for the treatment of anti-NMDA receptor encephalitis. The clinical presentation, diagnosis, treatment, surgical management, and prognosis, as well as a review of this disorder, were discussed in this case conference.