A 22-year-old woman develops psychiatric symptoms, orofacial dyskinesias, autonomic instability, and refractory seizures. MRI is unremarkable, but CSF shows lymphocytic pleocytosis. Antibodies against the NMDA receptor are detected. Which underlying tumor must be excluded in this patient?

• A Renal cell carcinoma
• B Small cell lung carcinoma
• C Medulloblastoma
• D Ovarian mature cystic teratoma ✓

Explanation

Anti-NMDA receptor encephalitis is a classic paraneoplastic neurologic syndrome in young women caused by antibodies directed against neuronal NR1 subunits, and it is strongly associated with ovarian teratomas containing neural tissue. Removal of the teratoma often improves the encephalitis. Small cell lung carcinoma is instead linked to anti-Hu limbic encephalitis and Lambert-Eaton myasthenic syndrome, which kills option B.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.