Tuberculosis of the sternoclavicular joint. Report of two cases.

The sternoclavicular joint accounts for only 1 to 2% of all cases of peripheral tuberculous arthritis and is more often infected by pyogenic organisms than by the tubercle bacillus. We report two cases of sternoclavicular joint tuberculosis, in a 38-year-old man and a 46-year-old woman without risk factors for immune deficiency. Swelling of the joint was the presenting manifestation. Laboratory tests indicated inflammation in only one of the patients. The intradermal tuberculin test was strongly positive in both patients, whereas smears and cultures of sputum and urine samples were negative for the tubercle bacillus. Serologic tests for the human immunodeficiency virus were negative. Erosions of the affected joint were seen by computed tomography. Histological studies of a surgical biopsy specimen confirmed the diagnosis. Cultures of the biopsy specimens were negative. The outcome was favorable after treatment with rifampin, isoniazid and pyrazinamide for six months in the man and nine in the woman. Follow-ups were eight and six months, respectively, at the time of this writing. Tuberculosis of the sternoclavicular joint is extraordinarily rare and can raise diagnostic problems. The diagnosis should be considered in every patient with arthritis in a sternoclavicular joint or unexplained pain in a shoulder. Possible complications include compression or erosion of the large blood vessels at the base of the neck and migration of tuberculous abscesses to the mediastinum.