Anti-N-methyl-D-aspartate receptor encephalitis associated with hepatic neuroendocrine carcinoma: A case report.

Anti-N-methyl-D-aspartate receptor (Anti-NMDAR) encephalitis can present with and without tumor. Tumor associations are less common in older patients. We report a 65-year-old gentleman who presented with one week history of cough, chills, rigor and altered behavior, followed by florid visual and auditory hallucinations. Mini mental status examination score was 16/30. Both cerebrospinal fluid and plasma anti-NMDA receptor antibodies were detected. A course of intravenous methylprednisolone was given with partial symptom improvement. A hepatic neuroendocrine carcinoma was detected and confirmed on biopsy. Unfortunately, he developed several medical complications: non-ST elevation myocardial infarction, infected foot gangrene and peripheral vascular disease, which made him unsuitable for both surgery and chemotherapy. He passed away 6months later due to the progression of the malignancy. This case illustrated that NMDAR encephalitis may be associated with an uncommon hepatic neuroendocrine carcinoma in an older person, which is responsive to early treatment.