Pericardial actinomycosis: case report and review.

Pericardial actinomycosis is rare and frequently goes unrecognized during life, a circumstance due in part to a paucity of clinical manifestations and to a low rate of positivity in cultures. We present a case report of pericardial actinomycosis and a review of 18 other cases reported in the literature since 1950. Possible risk factors include aspiration pneumonia, alcohol abuse, and periodontal disease. Actinomyces may cause purulent pericarditis that evolves into cardiac tamponade or constrictive pericarditis. Clues to the identity of the causative organism (e.g., draining sinus tracts and the presence of sulfur granules) are frequently absent, and cultures often fail to yield the organism. Histologic examination of material obtained by biopsy is often necessary to make the diagnosis. Most cases originate from a thoracopulmonary site of actinomycosis and spread directly to the pericardium. Widespread dissemination to extrathoracic organs is uncommon. Treatment consists of high-dose, long-term antimicrobial therapy as well as drainage of the pericardial space.