Paraneoplastic syndromes in urologic malignancy: the many faces of renal cell carcinoma.

Renal cell carcinoma is unique among the genitourinary malignancies in that close to one third of affected patients show signs and symptoms of a paraneoplastic syndrome. The paraneoplastic syndromes associated with renal cell carcinoma range from those manifesting in constitutional symptoms (ie, fever, cachexia, and weight loss) to those that result in specific metabolic and biochemical abnormalities (ie, hypercalcemia, nonmetastatic hepatic dysfunction, amyloidosis, etc). The presence of a paraneoplastic syndrome in a patient with renal cell carcinoma is neither a marker of metastatic disease nor necessarily indicative of a poor prognosis. The importance of understanding the pathophysiology and biology behind the many paraneoplastic syndromes associated with renal cell carcinoma lies in the fact that the presence of these protean symptoms may be the initial presentation of either primary or recurrent disease. In this review, we will describe the proposed mechanisms of action of the many paraneoplastic syndromes associated with renal cell carcinoma as well as outline the clinical evaluation and treatment options currently available for these noteworthy disorders.