More than teen angst: A case of ovarian teratoma presenting as anti-N-methyl-d-aspartate receptor encephalitis

Abstract

A 17-year-old nulligravid presented with labile mood, insomnia, and hyper-productive speech for 2 days, which progressed to seizures. Cerebrospinal fluid was positive for anti-N-methyl-d-aspartate (NMDA) receptor antibodies. Despite immunotherapy and seizure prophylaxis, she had status epilepticus and rapid decrease in sensorium. She was placed on ventilatory support and was admitted in the intensive care unit. On the 44th hospital day, an incidental finding of an ovarian teratoma was seen on abdominal computed tomography scan. She underwent right salpingo-oophorectomy, which revealed an immature teratoma. The absence of an intensive care admission and prompt surgery and immunotherapy are known predictors of good outcome in anti-NMDA receptor (NMDAR) encephalitis, with improvement seen in 80% of patients. Because most ovarian teratomas are only diagnosed as an incidental finding, anti-NMDAR encephalitis with a concurrent ovarian teratoma should be suspected in young females presenting with sudden-onset neuropsychiatric symptoms, to provide the timely intervention necessary for a good prognosis.