Paraneoplastic neuromyelitis optica associated with ANNA-1 antibodies in invasive thymoma

BACKGROUND: Thymoma is associated with various paraneoplastic autoimmune disorders. Herein, we report paraneoplastic neuromyelitis optica (NMO) associated with both anti-aquaporin-4 (AQP4) immunoglobulin G (IgG) and type 1 antineuronal nuclear antibody (ANNA-1) in an invasive thymoma patient. CASE PRESENTATION: A woman presented with a sudden onset of bilateral progressive visual loss associated with recurrence of invasive thymoma, 6 years after thymectomy and immunosuppressive treatment. AQP4-IgG and ANNA-1 were present in the patient’s serum. Visual outcome was poor despite immunosuppressive treatment. Longitudinally extensive transverse myelitis developed 27 months after the onset of visual symptoms. CONCLUSIONS: We have reported a case of paraneoplastic NMO associated with both AQP4-IgG and ANNA-1 autoantibodies in an invasive thymoma patient.