Neuromyelitis optica spectrum disorder with lung adenocarcinoma and intraductal papillary mucinous neoplasm.

Few cases reported the coexistence of tumors and neuromyelitis optica spectrum disorder (NMOSD), which is generally considered idiopathic. Here we describe a 61-year-old woman who developed anti-aquaporin-4 IgG positive myelitis with a pathologically-diagnosed lung adenocarcinoma and a radiologically-diagnosed intraductal papillary mucinous neoplasm. With corticosteroids and immunoglobulin in the acute phase and surgical resection of the lung adenocarcinoma, the patient recovered substantially. This case highlights the need for tumor screening in patients with NMOSD, especially those over 50 years old.