Anti-NMDA receptor encephalitis due to large-cell neuroendocrine carcinoma of the uterus

A 44-year-old woman presented with a large-cell neuroendocrine carcinoma and uterine endometrioid carcinoma with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Following the diagnosis of uterine cancer, the patient suddenly developed psychosis with abnormal behaviors, delusions, irritability, and forgetfulness. The cerebrospinal fluid tested positive for anti-NMDAR antibodies (encoding the NR1 subunit). The patient was diagnosed with paraneoplastic limbic encephalitis due to uterine cancer. Histology of multiple abdominal metastatic samples revealed a neuroendocrine tumor. Her consciousness improved temporarily after tumor resection and comprehensive immunomodulatory therapy. On day 104 after admission, the patient died of multiple organ failure. The autopsy revealed a perivascular infiltration of inflammatory cells in the amygdala and NMDAR-positive cells in the primary uterine cancer. Our findings demonstrated that neuroendocrine tumors can induce anti-NMDAR encephalitis, which is consistent with three previous reports. A comprehensive treatment with resection of the carcinoma, immunoglobulins, and plasma exchange can induce a partial improvement of the symptoms.