Which antibody and which cancer in which paraneoplastic syndromes?

Paraneoplastic neurological syndromes can be associated with the presence of onconeural antibodies. These antibodies are the result of an immune response against a tumour that is ectopically expressing a neuronal antigen. The 'classical' onconeural antibodies (anti-Hu, Yo, Ma2, CRMP-5, amphiphysin and Ri) are directed against intracellular antigens and are strongly associated with underlying malignancy. By contrast, onconeural antibodies directed against cell surface antigens (eg, anti-NMDA, VGKC, AChR) have a weaker tumour association. This article gives a practical overview of the tumour associations, and the neurological associations, of the onconeural antibodies. There is also guidance on how to investigate occult malignancy in antibody positive cases.