Failure to improve after ovarian resection could be a marker of recurrent ovarian teratoma in anti-NMDAR encephalitis: a case report

Abstract

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a type of autoimmune encephalitis that can be paraneoplastic and usually responds to tumor resection and immunotherapy. More than 75% of patients with anti-NMDAR encephalitis fully recover or have only mild sequelae, whereas the remainder experience severe disability. It remains unknown why certain cases have refractory clinical disease courses. We report a case of anti-NMDAR encephalitis with bilateral ovarian teratomas who was refractory to tumor resection and early initiation of immunotherapy. During intensive care, immunohistochemical analyses of her cerebrospinal fluid showed persistently high reactivity of NMDAR antibody over time. Six months after the operation, pelvic computed tomography detected a recurrent ovarian teratoma. After total enucleation of the bilateral ovaries, with significant pathological findings of bilateral mature cystic teratomas, her clinical condition improved rapidly, paralleled by a decrease in anti-NMDAR reactivity. This case illustrates the need to keep considering why extensive treatment fails to influence the disease when we encounter patients with refractory anti-NMDAR encephalitis. Failure to improve after ovarian resection could be a marker of recurrent ovarian teratoma in anti-NMDAR encephalitis.

Keywords:

• N-methyl-D-aspartate receptor
• antibody
• autoimmune encephalitis
• refractory
• recurrence

Acknowledgments

Written informed consent has been provided by the patient to have the case details and images published.

Author contributions

Y Uchida developed the hypotheses, created the figure, and wrote the first draft of the manuscript. D Kato developed the hypotheses and created the figure. Y Yamashita and Y Ozaki analyzed the clinical and pathological data. N Matsukawa developed the hypotheses and reviewed the manuscript. All authors contributed toward data analysis, drafting and critically revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.