Rate of Anti-NMDA Receptor Encephalitis in Ovarian Teratomas

Abstract

Background The rate of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) in ovarian teratomas is unknown. We aim to identify the prevalence of NMDARE as well as volumetric and histopathologic characteristics of ovarian teratomas in patients with versus without. Methods We performed a retrospective cohort study to identify patients with confirmed ovarian teratomas and the characteristics of teratomas in NMDARE compared with non-NMDARE patients. Patients aged between 0 and 21 years with confirmed histopathological diagnosis of ovarian teratoma after resection were included. The rate of NMDARE in ovarian teratomas was identified. Moreover, volumes of ovarian teratomas and the frequency of neuronal glial elements on histopathology in NMDARE versus non-NMDARE patients were assessed. Results Five out of one-hundred-and-sixty-three (3.07%) patients with histopathology confirmed ovarian teratomas were diagnosed with NMDARE. Age was not different between the NMDARE (mean: 13.8 years, standard deviation: 3.9) and non-NMDARE groups (median: 14, interquartile range [IQR]: 5). Teratoma volumes from NMDARE patients were smaller than those of non-NMDARE patients (median 28.3 cm3 with IQR of 431.2 and median 182.8 with IQR of 635.0, respectively). Both age and NMDARE diagnosis were statistically significant variables in the analysis of variance on a multiple linear regression model. Age (p = 0.013) had a positive correlation with teratoma size, whereas presence of NMDARE had a negative correlation (p = 0.008). Conclusion The rate of NMDARE in ovarian teratomas is low and NMDARE patients have smaller teratomas than non-NMDARE. Further studies are needed to understand the timing of anti-NMDA receptor antibodies in teratomas and the development of NMDARE.

A Mysterious Case of Encephalitis: Diagnostic Challenge and Our Clinical Reasoning

“…Still, a few reports aimed at identifying the prevalence of anti-NMDAR encephalitis indicated that the rate of NMDAR encephalitis in ovarian teratomas is low, and NMDAR encephalitis patients have smaller teratomas than non-NMDAR encephalitis patients. They have concluded that further studies are needed to understand the timing of anti-NMDA receptor antibodies in teratomas and the development of NMDAR encephalitis [ 3 ]. The sensitivity of anti-NMDA receptor antibody testing is higher in CSF than in serum.…”

The Leading Role of Brain and Abdominal Radiological Features in the Work-Up of Anti-NMDAR Encephalitis in Children: An Up-To-Date Review

“…According to the recent “Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes”, NMDARe are considered neurologic syndromes at “intermediate risk”, associated with cancer in 30–70% of cases (mostly ovarian or extraovarian teratomas, such as mediastinal localizations), especially in females between 12 and 45 years of age (50% of all patients) [ 10 , 18 ]. On the other hand, women with ovarian teratomas generally have a low prevalence of anti-NMDAR antibodies, and those who develop autoimmune encephalitis seem to have smaller teratomas than those without NMDARe [ 10 ]. Meanwhile, paraneoplastic NMDARe are extremely rare in males and children under the age of 12 (less than 10%) [ 7 , 8 ].…”

“…If the disease does not improve in 1–3 months after the beginning of first-line and second-line therapy, the use of cyclophosphamide can be considered at a dosage of 500–1000 mg/m 2 (maximum 1500 mg) in monthly pulses for up to 6 months. However, a primary tumour resection is the most important therapeutic step in paraneoplastic NMDARe [ 10 , 53 , 54 ]. Children with no teratoma-associated encephalitis have a less favorable response to therapy.…”

“…Autoantibody serology, cerebrospinal fluid (CSF) analysis, and imaging techniques are all helpful in making a diagnosis when a patient’s history is hardly suggestive [ 9 ]. Ultrasonography (US) and other imaging methods, such as abdominal computed tomography (CT) and brain magnetic resonance imaging (MRI), are key tools for the correct work-up of NMDARe [ 4 , 10 , 11 ]. As shown in the relevant brain MRI findings described in detail in this paper, the brain disruption may be relevant in this rare disorder, often allowing serious cognitive and psychiatric morbidity.…”

Sleep Characteristics in Pediatric Anti–N-methyl-d-aspartate (NMDA) Receptor Encephalitis: A Retrospective Cohort Study

“…3-5 Although rare, NMDA receptor encephalitis is more common than infectious encephalitis, including herpes simplex virus (HSV) and West Nile Virus encephalitis, in people <25 years old. 6 NMDA receptor encephalitis can develop as a paraneoplastic response to tumors, such as ovarian teratomas, 1,7 or after HSV encephalitis. 8 The presence of ovarian teratomas is more common in adolescents or adults compared to children.…”