Malignancy as a possible complication of complex regional pain syndrome: a case report.

A synovial sarcoma presented in the knee of a young woman 20 years after the onset of pain which was attributed to complex regional pain syndrome (CRPS). Was this a chance occurrence, or could there be any link between the two conditions? Did the pain itself and the persistent inflammatory and immunological response to pain contribute to the development of malignancy, or could the malignancy have been present subclinically for many years and have contributed to the ongoing pain syndrome? This case report looks into the diagnosis of synovial sarcoma and CRPS and the relationship between the neurogenic inflammation seen in CRPS and that seen in malignancies. The diagnosis of CRPS is a diagnosis of exclusion.