Mycobacterium avium: a potentially treatable cause of pericardial effusions

We present a patient with a very large pericardial effusion due to disseminated Mycobacterium avium complex (MAC) infection with associated bacteraemia and gastroenteritis. He was HIV antibody-positive with a CD4+ lymphocyte count of 10 x 10(6)/l. He complained of fevers, diarrhoea and dyspnoea and an echocardiogram showed a pericardial effusion. Chest X-ray showed progressive enlargement of the cardiac silhouette over a 3-month period. The effusion was drained surgically and antimycobacterial therapy (clarithromycin, clofazamine, rifampicin, ciprofloxacin, amikacin) was initiated. The patient had complete resolution of his pericardial effusion both clinically and radiologically. Three other AIDS patients with pericardial effusions caused by MAC are described in the medical literature, two died of cardiac dysfunction shortly after diagnosis. There is a case described of MAC-related pericardial effusion in a HIV-negative immunocompetent patient which resolved antimycobacterial therapy. MAC should be included in the differential diagnosis of pericardial effusions in AIDS patients. A combination of medical therapy and surgical intervention may give rise to considerable clinical benefit especially if initiated early.