“…They can result from bone and joint invasion by the tumor (metastasis to the musculoskeletal system) [2][3][4], synovial reaction to neoplastic cells nearby [3,4], hemorrhage into the joint [4], secondary gout [3,4], complications from cancer treatments [2], neoplasia secondary to rheumatic diseases [2], malignancies secondary to immunosuppressive [2], and finally paraneoplastic syndromes [2][3][4]. This paper will focus on the last one: rheumatic diseases as paraneoplastic syndrome, which consist on symptoms caused by the malignancy, not directly related to the tumor mass or the metastasis [2]. They occur in 10% at the time of diagnosis, but almost 50% on the course of the neoplasia [2,3].…”