RESOLUTION OF A SOFT-TISSUE SARCOMA IN A PATIENT WITH RHEUMATOID-ARTHRITIS AFTER DISCONTINUATION OF AZATHIOPRINE THERAPY

An 85-year-old woman with rheumatoid arthritis that was treated with a zathioprine presented with a posterior thoracic soft-tissue mass. A co mputed tomographic scan demonstrated a large mass in the chest wall th at extended into the pleural space and several pulmonary nodules that were consistent with metastatic disease. A fine-needle biopsy was perf ormed, and a morphologic diagnosis of sarcoma was made. As the patient was relatively asymptomatic and the lesion was inaccessible to a surg ical procedure, no therapy was recommended. Therapy with azathioprine was discontinued. One year later, the mass had resolved. To our knowle dge, this is the first reported case of a soft-tissue sarcoma complica ting azathioprine treatment of rheumatoid arthritis.