Posterior reversible encephalopathy syndrome in a patient with paraneoplastic extralimbic encephalitis and small cell lung cancer

Background: Paraneoplastic encephalomyelitis (PEM) is a multifocal infl ammatory disorder of the central nervous system (CNS) associated with remote neoplasia. Case report: We describe a 41-year-old female patient with subacute development of dysarthria, dysphagia, tetraparesis, ataxia, breathing diffi culties and cognitive deterioration. Brain magnetic resonance imaging revealed multiple confl uent hyperintense lesions in cortical and subcortical white matter consistent with the posterior reversible encephalopathy syndrome. Ultimately, she was diagnosed with anti-Hu positive paraneoplastic extralimbic encephalitis and small cell lung cancer. Treatment with intravenous corticosteroids and immunoglobulins led to minimal clinical improvement, while signifi cant regression of bilateral symmetric cortical edema and edema of subcortical white matter was seen on follow up brain magnetic resonance imaging. Conclusion: Th e paraneoplastic extralimbic encephalitis and posterior reversible encephalopathy syndrome are rare fi rst manifestations of small cell lung cancer.