Paraneoplastic Teratoma-associated Anti-N-Methyl-D-Aspartate Receptor Encephalitis: The First Published Report from Saudi Arabia

Paraneoplastic teratoma-associated anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis is a lately introduced disease that was first documented in 2007. In a recent systemic review in 2014, only a total of 174 cases of teratoma-associated anti-NMDA receptor encephalitis was reported. Herein, to the best of our knowledge, in Saudi Arabia, we report the first ever case of mature ovarian teratoma-associated anti-NMDA receptor encephalitis in a 21-year-old Saudi woman who presented to clinical attention with a nine-day history of neuropsychiatric symptoms preceded by a two-day flu-like illness. Central nervous system (CNS) examination was remarkable for confusion and an inability to move her lower limbs. Abdominal examination was remarkable for mild right lower quadrant tenderness without palpable organomegaly. Initial laboratory findings were remarkable for high CA-125 level of 205 units/ml (normal: 0 - 35 units/ml) and CA 19-9 level of 121 units/ml (normal: 0 - 37 units/ml). Cerebrospinal fluid (CSF) examination showed lymphocytic pleocytosis and oligoclonal bands. Computed tomography (CT) scan of the abdomen and pelvis showed a 7.2 x 6.3 x 5.5 cm mass of the right ovary that was highly suspicious for a mature teratoma with fat densities and calcified foci. Serum and CSF tested positive for anti-NMDA receptor antibodies. The patient underwent right oophorectomy and the final histopathological diagnosis was confirmed. Postoperatively, the patient had an uneventful postoperative course and did not receive adjuvant secondary immunotherapies. One day following the surgery, her neuropsychiatric symptoms improved dramatically. At a six-month follow-up at the outpatient clinic, the patient was symptom-free.