Background: In a minority of patients with neuromyelitis optica spectrum disorder (NMOSD) and aquaporin-4 antibodies (AQP4-IgG), the disease has a paraneoplastic origin. It is unknown whether these patients have distinctive clinical features.
Objective: To report the clinical features of a series of patients with paraneoplastic NMOSD and AQP4-IgG and to review previously reported cases.
Methods: Retrospective analysis of clinical records of 156 patients with NMOSD and AQP4-IgG and review of previously reported patients with paraneoplastic NMOSD and AQP4-IgG. Paraneoplastic patients were defined as those with cancer identified within 2 years of the diagnosis of NMOSD.
Results: Five (3.2%) of 156 patients had paraneoplastic NMOSD, and 12 previously reported patients were identified. The most common tumors were adenocarcinoma of the lung (five patients) and breast (five). Compared with the 151 non-paraneoplastic NMOSD patients, the 17 (5 current cases and 12 previously reported) were older at symptom onset (median age = 55 (range: 17-87) vs 40 (range: 10-77) years; p = 0.006), more frequently male (29.4% vs 6.6%; p = 0.009), and presented with severe nausea and vomiting (41.2% vs 6.6%; p < 0.001). The frequency of longitudinal extensive transverse myelitis (LETM) as heralding symptom was similar in both groups, but patients with paraneoplastic NMOSD were older than those with non-paraneoplastic NMOSD (median age: 63 (range: 48-73) vs 43 (range: 14-74) years; p = 0.001).
Conclusion: Patients, predominantly male, with NMOSD and AQP4-IgG should be investigated for an underlying cancer if they present with nausea and vomiting, or LETM after 45 years of age.
Keywords: AQP4 antibodies; Neuromyelitis optica spectrum disorders; cancer; paraneoplastic.