[Bone and calcium metabolism associated with malignancy. Paraneoplastic rheumatologic musculoskeletal manifestations.]

Patients with malignant tumors may present with joint pain or arthritis(paraneoplastic arthritis). It needs to be carefully determined whether these symptoms are related to the malignant tumor, due to a concomitant rheumatoid disease, due to an adverse reaction to treatment, or due to a relapse. It can be relatively easy to diagnose paraneoplastic syndrome when there is clearly a malignant tumor present or typical symptoms are exhibited. However, clinicians should be aware that these paraneoplastic syndrome phenomena can occur before the malignant tumor is diagnosed. An occult malignancy should be suspected when a patient is elderly and exhibits atypical clinical symptoms of a rheumatic disease;is poorly responsive to usual treatment;or has general symptoms such as weight loss or exhibits suggestive physical findings. In particular, hematological malignancies require careful observations as they do not surface quickly.