Occult Growing Teratoma as the Cause of Protracted Symptoms in a Patient with Anti-NMDA-Receptor Encephalitis and Prior Ovarian Teratoma Removal: Implications for Continued Monitoring and Treatment

Abstract

Dear Editor, Anti-NMDA-receptor encephalitis (NMDARE) is largely a monophasic, infrequently relapsing autoimmune condition, with most patients improving after the initial episode and returning to their premorbid functional status if timely and appropriate treatment is administered.1 In a small proportion of cases, the initial episode may be followed by relapses and cumulative deterioration that persist despite continued immunosuppressive and immunomodulatory treatment.1 Such a malignant course occurs less frequently in patients with ovarian teratomas that have been successfully and promptly resected.2 We report a case of NMDARE in which persistent symptoms refractory to continued treatment completely disappeared after the discovery and removal of a second teratoma. Our case highlights the importance of continued monitoring for teratomas and other neoplasms in patients with persistent symptoms of NMDARE. An 18-year-old female presented with headache, altered mental state, and seizures to the emergency room, where pleocytosis was detected in the cerebrospinal fluid (CSF). A course of acyclovir was administered, but there was no clinical response and the patient quickly succumbed to a comatose mental state that was accompanied by excessive salivation, oromandibular and whole-body dyskinesia, and hypoventilation. Electroencephalography revealed an extreme delta-brush pattern. A suspected diagnosis of NMDARE was confirmed with CSF and serum antibody testing. A right ovarian teratoma found on CT was removed, and the absence of remaining teratoma tissue was confirmed in a follow-up abdominopelvic CT. She promptly received intravenous immunoglobulins (IVIg), intravenous steroids, rituximab, tocilizumab, and low-dose interleukin-2, electroconvulsive therapy, and up to five antiseizure medications (ASMs) during her first hospitalization, which lasted for a little over 1 year (Fig. 1). She regained alertness during the course of her treatment, but her fluency remained limited to single words when she was discharged. She continued to receive ASMs during 2 years of outpatient follow-up, as well as further immunotherapy consisting of bortezomib and IVIg boosts due to persistent breakthrough seizures and cognitive symptoms. Although she was able to speak in sentences of a few words, she continued to complain of short-term memory impairment and emotional lability. She reported menstrual irregularity at 4 years after the start of her illness and so was referred to the gynecology department. MRI of her pelvis revealed a sizable teratoma causing left ovarian torsion, which was resected. Remarkably, in the neurology outpatient clinic 2 weeks after her surgery, she reported the complete resolution of all of the cognitive and mood sympSang Bin Hong* Yong-Won Shin* Yong Woo Shin Sang Kun Lee Kon Chu