Clinical Case of the Month. A 44-Year-Old HIV-Infected Man With Righ-Shoulder Swelling.

: Immunocompromised patients are susceptible to various joint infections with less-common pathogens, such as mycobacterium. Physicians should have a low threshold to investigate the cause of an arthropathy further. An aspiration of the effusion is usually warranted to identify the possible pathogen and target treatment. We report an unusual presentation of a human immunodeficiency virus-infected patient with a chronic effusion arthropathy of his right shoulder due to Mycobacterium kansasii. We review the risk factors, transmission, clinical manifestations, and management of Mycobacterium kansasii.