To describe reversible extralimbic paraneoplastic encephalopathies with large, lobar lesions on magnetic resonance imaging (MRI).
Autoimmune Neurology Clinic, Mayo Clinic, Rochester, Minnesota.
Three patients had large confluent areas of signal abnormality on T2-weighted MRI, including frontal in 2 and frontal and occipital in 1. Patient 1, a woman aged 63 years, experienced hemiparesis with hemianopia 3 years after a diagnosis of adenocarcinoma of the breast. Nine years later, rapidly progressive dementia developed. Patient 2, a woman aged 79 years, presented with monoparesis and epilepsia partialis continua, 1 year after a diagnosis of adenocarcinoma of the breast. Patient 3, a man aged 65 years, had paraneoplastic sensory neuronopathy, limbic encephalitis, antineuronal nuclear autoantibody type 1 (ANNA-1), and squamous cell carcinoma of the lung. He was stable for 3 years after treatment. Subacute onset of aphasia, delirium, worsening seizures, and rising ANNA-1 titers led to a diagnosis of recurrent limited carcinoma. Brain MRI abnormalities in all patients improved dramatically after immunotherapy. Two patients had sustained clinical remission.
Recognition of paraneoplastic extralimbic lobar encephalopathies is important because these disorders and their underlying cancers are treatable.