RESUMO
Paraneoplastic limbic encephalitis is a rare disorder that is characterized by personality changes, irritability, depression, seizures, memory loss and dementia, and is commonly associated with small cell lung cancer. The cause is unknown but it is believed to be an autoimmune disorder that develops secondary to a carcinomatous process. We report a patient with the clinical feature consistent with limbic encephalitis. A 64-year-old women developed disorientation, memory loss and general weakness. She was diagnosed with NSCLC (adenocarcinoma) with a brain metastasis 1 year earlier and was treated with radiation and chemotherapy. Although the lung mass and brain metastatic lesions had improved, the brain T2-weighted MRI showed high signal intensity in the right temporal region. This lesion consisted of with limbic encephalitis and was negative to the other viral and immune markers. The patient's symptoms did not improve after steroid treatment. Our case demonstrated that a NSCLC (adenocarcinoma) also can be associated with paraneoplastic limbic encephalitis.