Risk of development of malignant tumors increases in elderly people. There are numerous clinical symptoms mimicking primary rheumatic diseases in the course of cancers, referred to as paraneoplastic rheumatologic syndromes. They are not caused directly by the tumor or its metastases, but result from the action of biologically active substances released by cancer cells and abnormal immunological reactions. Paraneoplastic rheumatologic syndromes may precede the diagnosis of cancer, occur simultaneously or occur after the diagnosis of malignancy. In clinical practice, it is very difficult to distinguish paraneoplastic syndromes from idiopathic rheumatic diseases. However, some clinical features may suggest the paraneoplastic nature of rheumatic diseases, including the onset of symptoms in old age, atypical and rapidly progressive course or poor response to conventional treatment. Early and well-targeted diagnostics allow the diagnosis of often latent neoplasm, and its effective treatment may lead to resolution of paraneoplastic rheumatic symptoms. This paper discusses selected paraneoplastic rheumatologic syndromes that often occur in older people, including carcinomatous polyarthritis, remitting seronegative symmetrical synovitis with pitting edema (RS3PE), palmar fasciitis-polyarthritis syndrome, hypertrophic osteoarthropathy, tumor-induced osteomalacia, cancerassociated myositis, paraneoplastic scleroderma like syndrome, paraneoplastic vasculitis and paraneoplastic Raynaud's syndrome.
Keywords: cancer-associated myositis; paraneoplastic arthritis; paraneoplastic bone disease; paraneoplastic scleroderma like syndrome; paraneoplastic syndrome; paraneoplastic vasculitis; rheumatic diseases.