Chronic monoarthritis and foot-drop as a paraneoplastic syndrome in prostate cancer.

Paraneoplastic rheumatic symptoms, caused by a malignancy, but not directly related to invasion by the tumor or its metastases are the result of a wide variety of tumor-derived biologic mediators. Recognition of paraneoplastic rheumatic syndromes is important, as it may lead to an early diagnosis of cancer. We report a 71-year-old patient with prostate cancer, presented with chronic monoarthritis of the left ankle and foot-drop. Monoarthritis and foot-drop was resistant to non-steroidal anti-inflammatory drugs and corticosteroids. After tumor resection, synovitis resolved and foot-drop disappeared almost totally.