A case of paraneoplastic cerebellar degeneration associated with small cell lung cancer

Paraneoplastic cerebellar degeneration (PCD) is a clinical syndrome and known to be occasionally associated with small cell carcinoma of the lung (SCLC). PCD usually affects patients before the cancer is evident. The disorder evolves subacutely, and causes severe pancerebellar dysfunction. In this paper, we report a case of PCD associated with SCLC. A 65-year-old man presenting with 2 weeks of progressive vertigo, gait ataxia, and speech disturbance, was readmitted to our hospital. He had earlier been given a diagnosis of SCLC, oat cell carcinoma, and had undergone high-dose chemotherapy with peripheral blood stem cell transplantation during his first admission. Following that treatment regimen, the tumor disappeared completely and the patient had been in remission. Based on neurological findings and the presence of anti-neuronal antibodies a diagnosis of PCD was made. Although cyclophosphamide (500 mg/m2) was administered, the patient experienced no relief of his cerebellar ataxia. Six months afer readmission, he died of cardiac tamponade due to malignant pericarditis. A histological examination at autopsy found few Purkinje cells and a proliferation of Bergmann's astrocytes in the cerebellar cortex. These findings were consistent with the diagnosis of PCD.