Rheumatic manifestations of neoplasia.

Neoplasia in an important cause of rheumatic disease. The mechanisms are either direct infiltration of the bone and joint, or indirect infiltration with manifestations distant from the site of neoplastic involvement. Many of the reports reviewed in this article center on direct associations. In particular, there is a report on polymyositis and dermatomyositis and the link with neoplasia. Cases of reflex sympathetic dystrophy are also described in association with neoplasia. There is further discussion on the link of hairy cell leukemia and vasculitis. Other case reports highlight the multiple associations of musculoskeletal disease and neoplasia. These reports include patients with subcutaneous sarcoidosis, ankylosing spondylitis, polychondritis, and systemic sclerosis. Articular manifestations of benign pleural fibromas are described. The existence of these reports, however, does not constitute proof of a causal relationship and the possibility of chance occurrences of two conditions must be considered. Finally, various therapies for cancer are associated with rheumatologic manifestations. Intravesical bacillus Calmette-Guérin has been found to cause an inflammatory polyarthritis. This form of arthritis is similar to experimentally induced adjuvant arthritis in rats that follows immunization with Freund's adjuvant containing Mycobacterium tuberculosis.