Astrocytoma with myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis: A case report.

Background: Demyelination is similar with malignancy in clinical symptoms. Magnetic resonance imaging (MRI) is an important auxiliary examination in the diagnosis of demyelinating diseases and malignancy. Since MRI and symptoms can be difficult to distinguish demyelination from malignancy, other auxiliary examinations, such as demyelinating disease-specific antibodies, play an important role in distinguishing them. Previous studies have reported demyelinating disease-specific antibodies in patients with malignancy. What's more, it is more difficult to confirm the diagnosis when the malignant tumor co-occurs with demyelinating diseases, which has never been reported in previous studies. We report the diagnosis of myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis (MOG-EM) in a patient who had astrocytoma for several years.

Case Presentation: Patient's concerns and diagnoses: our case report records a 49-year-old woman with astrocytoma for more than 4 years, who recently developed the symptoms of MOG-EM, including dizziness, vomiting, and vision loss. This astrocytoma patient was diagnosed with MOG-EM according to comprehensive evidence, including MRI, visual evoked potential (VEP), serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG), and therapeutic effect. Interventions and outcomes: this patient was diagnosed with astrocytoma by surgical biopsy 4 years earlier. This patient has been treated with tumor resection, postoperative radiation treatment and chemotherapy. After treatment, the patient was left with right limb weakness while other symptoms were improved. Recently, the intravenous steroid agent was used to treat this patient after being diagnosed with MOG-EM. Dizziness, vomiting, and vision loss have gone into remission. This patient did not relapse in 7 months after discharge. This patient is still being followed up at the outpatient clinic. And the patient will next be treated with azathioprine.

Conclusions: In previous studies, polyclonal antibody has been found in cancer patients, such as aquaporin-4 and MOG-IgG in astrocytoma patients. But the case of our study finds that astrocytoma can coexist with MOG-EM. Therefore, MOG-EM should not be excluded easily in astrocytoma patients when the relative antibody of encephalomyelitis is positive. What's more, it reminds us that the pathogenesis of MOG-EM might be related to astrocytoma.