Importance
Reports of neuromyelitis optica spectrum disorder (NMOSD) occurring in the setting of neoplasia suggest that aquaporin-4 autoimmunity may in some cases have a paraneoplastic basis.Observations
In this case report, we describe a patient with NMOSD whose test results were seropositive for aquaporin-4 IgG and who had a hepatic metastasis from a small-bowel neuroendocrine tumor. The tumor cells expressed aquaporin-4 immunoreactivity. She presented to the Neurology Department at Wayne State University with bilateral leg weakness, ascending paresthesias, and decreased sensation.Conclusions and Relevance
This case extends the context of NMOSD as a paraneoplastic disorder.