Paediatric anti-NMDA-receptor encephalitis with ovarian teratoma

Herein, we report two paediatric cases of ovarian teratoma-associated anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. We performed surgical resection of the teratomas—enucleation in case 1 and salpingo-oophorectomy in case 2. The pathological diagnoses were immature teratomas with a small number of neuroglial elements, and cerebrospinal fluid (CSF) anti-NMDAR antibody test was positive in both cases. In case 1, the patient showed excellent recovery, and in case 2, neurological symptoms gradually improved. Paediatric cases of ovarian teratoma-associated anti-NMDAR encephalitis are rare, and early surgical resection and immunotherapy are important for good prognosis. We highlight the occurrence of paediatric cases of ovarian teratoma-associated anti-NMDAR encephalitis to create awareness and highlight the importance of surgical resection despite severe neurological symptoms.