Synovitis due to atypical mycobacteriosis is often difficult to diagnose, because it presents with nonspecific clinical findings. We describe a case of wrist tendon sheath synovitis due to atypical mycobacteriosis, which was complicated by rheumatic arthritis. The patient was a 66-year-old woman with rheumatic arthritis. She was found to have synovitis on the palmar side of the right wrist in June 2006 and underwent synovectomy. Pathological examination of the synovial tissue extracted during surgery showed, only findings of rheumatic arthritis, and atypical mycobacteriosis was not diagnosed. Because swelling recurred after surgery, we performed synovectomy a second time. Culture for bacterial and, the tubercle bacillus and the polymerase chain reaction for atypical mycobacteriosis were all negative. Swelling recurred after the second synovectomy. Mycobacterium avium and, Mycobacterium intracellulare were identified in fluid obtained from puncture of the swollen wrist area, therefore, we started chemotherapy and performed synovectomy a third time. Swelling has not recurred in the year since the third synovectomy was performed. We believe that atypical mycobacteriosis should be considered when intractable wrist tendon sheath synovitis occurs.
