Paraneoplastic progressive supranuclear palsy syndrome in a patient with B-cell lymphoma.

An important component in the diagnosis of atypical parkinsonian disorders is the exclusion of secondary causes. Paraneoplastic causes of parkinsonism are extremely rare. We describe a case which presented initially as probable progressive supranuclear palsy (PSP) but on follow-up displayed a rapidly progressive course, unexplained fever, peripheral neuropathy and an abnormal CSF. We highlight the difficulties faced in formulating a diagnosis for this unusual case prior to the discovery of an occult B-cell lymphoma, and discuss its relevance in the exclusion criteria for PSP. A paraneoplastic cause should be considered if disease progression is unusually rapid.