摘要:Introduction. Neuromyelitis optica spectrum disorder (NMOSD) is a rare demyelinating immune-mediated central nervous system disease. It is extremely rare to occur in patients with systemic lupus erythematosus (SLE), and it represents a diagnostic and therapeutic challenge. Case report. A 38-year-old Caucasian woman with medical history of SLE and new onset of flaccid paraparesis, fecal and urinary incontinence, persistent nausea and vomiting was admitted to our hospital. Based on the clinical presentation, magnetic resonance imaging findings and positive aquaporin 4 (AQP4) antibodies, a NMOSD with coexisting SLE were diagnosed. Pulse-doses of cyclophosphamide and glucocorticoids were efficient in patient treatment. Conclusion. In a patient with SLE and symptoms of longitudinal extensive transverse myelitis and/or optic neuritis and area postrema syndrome, assessment of AQP4 antibodies is neccessary for diagnosing NMOSD. Accurate diagnosis, and timely and long-term administration of immunosuppressive therapy are crucial for favorable outcome of these two coexisting diseases.