Contributor: Gordon K. Klintworth
A paraneoplastic syndrome is a syndrome that occurs as an epiphenomenon in a person with a neoplasm that is not directly related to the tumor but to some secondary effect. Examples are cancer associated retinopathy, secondary polycythemia [polycythemia - secondary], ateral diffuse uveal melanocytic proliferation, acanthosis nigrans, stiff person syndrome, paraneoplastic pemphigus [pemphigus - paraneoplastic], and cerebellar ataxia syndrome. A disorder of plasma cells causing  a monoclonal gammopathy may be associated with a neoplasm in one of several organs (paraneoplastic gammopathy).