Anti-NMDA Receptor Encephalitis Associated with Ovarian Teratoma: A Comprehensive Review.

Anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR-E) is a severe autoimmune encephalitis that predominantly affects young women and is frequently associated with ovarian teratomas. Increasing evidence indicates that these tumors play a central role in disease initiation by providing a peripheral immunological trigger. This comprehensive review summarizes current knowledge on the immunopathogenesis, clinical manifestations, diagnostic approach, therapeutic strategies, and long-term outcomes of ovarian teratoma-associated anti-NMDAR-E. We discuss the unique immunogenic properties of ovarian teratomas, including the presence of neuroglial tissue expressing the GluN1 receptor subunit (formerly known as NR1) of the N-methyl-D-aspartate receptor (NMDAR), dense immune cell infiltrates, and tertiary lymphoid structure-like formations that support local antibody production. These features are thought to promote molecular mimicry and loss of immune tolerance, leading to B-cell activation, intrathecal antibody synthesis, and antibody-mediated neuronal dysfunction. Furthermore, we review the characteristic multistage clinical course, key diagnostic findings in cerebrospinal fluid, imaging and electrophysiology, and the importance of early tumor removal combined with immunotherapy. Emerging therapeutic approaches and experimental models that provide insight into disease mechanisms and novel treatment targets are also highlighted. An improved understanding of tumor-driven neuroimmunological interactions is essential for earlier diagnosis, optimized treatment strategies, and better long-term outcomes in affected patients.