Anti-Yo positive paraneoplastic cerebellar degeneration in the setting of cholangiocarcinoma.

Paraneoplastic neurological syndromes are a rare complication of malignancy. Subacute cerebellar ataxia, or paraneoplastic cerebellar degeneration, usually presents in women with a subcate onset of gait instability, followed by progressive limb and trunk ataxia, dysarthria, diplopia, and dysphagia that occurs in the setting of, or precedes the diagnosis of, a gynecologic or breast malignancy and clinically stabilizes within six months. The most common autoantibody associated with PCD is purkinje cell cytoplasmic antibody type 1, also known as anti-Yo. Here we describe the first reported case of a man with anti-Yo positive paraneoplastic cerebellar degeneration in the setting of occult cholangiocarcinoma.