MicroRNA (miRNA) is a small non-coding RNA that functions in epigenetics control of gene expression, which can be used as a useful biomarker for diseases. Anti-NMDA receptor (Anti-NMDAR) encephalitis is an acute autoimmune disorder. Some patients were found to have tumors, especially teratoma. It occurs more often in female than in male. Most of them have a significant recovery after tumor resection. It reveals that the tumor may induce anti-NMDAR encephalitis. In this study, we review microRNA (miRNA) biomarkers that associate with anti-NMDAR encephalitis and related tumors, respectively. To the best of our knowledge, there have not been any researches in the literature investigating the relationship between anti-NMDAR encephalitis and tumors through their miRNA biomarkers. We adopt a phylogenetic analysis to plot the phylogenetic trees of their miRNA biomarkers. From the analyzed results, we may explain that (i) there is a relationship between these tumors and anti-NMDAR encephalitis, and (ii) this disease occurs more often in female than in male. This sheds light on exploring this issue through miRNA intervention.