A case of ovarian teratoma with anti-NMDA receptor encephalitis successfully treated by prompt laparoscopic surgery

We present a case report of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis that was successfully treated by prompt laparoscopic salpingo-oophorectomy.Case: A-35-year-old woman with no relevant medical history was admitted to another hospital after suddenly experiencing psychosis and hallucinations. She developed hypoventilation requiring mechanical support. She was transported to the Department of Neurology in our hospital 14 days after symptom onset. T1-weighted pelvic MRI showed a lesion 17 mm in diameter in her right ovary. As paraneoplastic limbic encephalitis was suspected, she was immediately scheduled for tumor resection the next day. She underwent laparoscopic right salpingo-oophorectomy and was afterward treated with high-dose intravenous methylprednisolone, plasma exchange and intravenous immunoglobulin. Four weeks later, she was able to follow simple commands, although she remained on mechanical ventilation for 10 weeks due to nocturnal central hypoventilation. Anti-NMDAR antibodies were detected in her cerebrospinal fluid. Pathological examination of the removed lesion showed an mature cystic teratoma. The patient was diagnosed as having anti-NMDA receptor encephalitis. She recovered completely and returned to work 8 months after onset of the disease.