Portal de Periódicos da CAPES

Cardiac Actinomycosis: An Unusual Cause of an Intracardiac Mass

2006; Elsevier BV; Volume: 19; Issue: 12 Linguagem: Inglês

10.1016/j.echo.2006.08.027

1097-6795

Grant L. Peters, Ross A. Davies, John P. Veinot, Ian G. Burwash,

Head and Neck Anomalies

Actinomycosis is a chronic disease characterized by abscess formation, tissue fibrosis, and draining sinuses that may involve the cervicofacial area, thorax, abdominopelvic region, or central nervous system. We describe a patient with cardiac actinomycosis presenting with pericardial disease and an intracardiac mass. The diagnosis failed to be obtained by pericardiocentesis, but was obtained after echocardiographically guided biopsy of the intracardiac mass. The patient recovered with long-term penicillin therapy. A review of the literature highlights the frequent pericardial presentation of cardiac actinomycosis, the potential difficulty in making the diagnosis, and the remarkable clinical response and good prognosis that can result when the correct diagnosis is made and appropriate antibiotic therapy administered. Actinomycosis is a chronic disease characterized by abscess formation, tissue fibrosis, and draining sinuses that may involve the cervicofacial area, thorax, abdominopelvic region, or central nervous system. We describe a patient with cardiac actinomycosis presenting with pericardial disease and an intracardiac mass. The diagnosis failed to be obtained by pericardiocentesis, but was obtained after echocardiographically guided biopsy of the intracardiac mass. The patient recovered with long-term penicillin therapy. A review of the literature highlights the frequent pericardial presentation of cardiac actinomycosis, the potential difficulty in making the diagnosis, and the remarkable clinical response and good prognosis that can result when the correct diagnosis is made and appropriate antibiotic therapy administered. Actinomycosis is a chronic indolent disease characterized by abscess formation, tissue fibrosis, and draining sinuses that may involve the cervicofacial area, thorax, abdominopelvic region, or central nervous system.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar The condition is caused by an infection with gram-positive anaerobic bacilli (Actinomycoses species), a normal inhabitant of the human flora. Cardiac actinomycosis is a rare disease, and usually involves the pericardium.2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar, 3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Unfortunately the disease is difficult to diagnose, potentially leading to a delay or failure to deliver appropriate treatment that can result in dramatic clinical improvement.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar, 3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar We describe a patient presenting with pericardial disease and an intracardiac mass, diagnosed as cardiac actinomycosis after an echocardiographically guided biopsy, and review the literature on this rare, but imminently treatable disease entity.Case reportA 51-year-old man was referred to our hospital for evaluation of a pericardial effusion and possible cardiac tamponade. He had been well up until 1 month before admission. At that time, he presented to a community hospital with a 2-week history of progressive pleuritic retrosternal discomfort, worse in the supine position. His chest discomfort had been preceded by a 2-day history of flu-like symptoms including fever, malaise, myalgia, and arthralgia. He was diagnosed with pericarditis, and treated with an anti-inflammatory medication. His chest discomfort initially improved, but he continued to have severe fatigue. Two weeks later, he had a recurrence of his fever with progressive pleuritic chest discomfort and dyspnea that prompted his return to the community hospital. He was hemodynamically stable, although clinically, there were findings suggestive of cardiac tamponade. An electrocardiogram demonstrated diffuse ST-T wave changes and PR depression consistent with pericarditis and a chest radiograph demonstrated an enlarged cardiac silhouette. He was transferred to our hospital for further treatment.On arrival at our center, the patient had a sinus tachycardia at 120/min and a blood pressure of 121/59 mm Hg. His respiratory rate was 20 breaths/min (oxygen saturation was 98% on 2 L/min oxygen by nasal prongs). He was febrile (38.9°C). Physical examination demonstrated an elevated jugular venous pressure at 8 cm and a positive Kussmaul's sign. Heart sounds were normal with no murmurs, extra heart sounds, or pericardial rub. There were bibasilar inspiratory crackles. There was no peripheral edema, but clubbing of the extremities was present. Hemoglobin was 93 g/L and the white blood cell count was 14.8 × 109/L (82% neutrophils). An electrocardiogram demonstrated diffuse ST-T wave changes with evidence of PR segment depression consistent with pericarditis. An echocardiogram demonstrated a large pericardial effusion with right ventricular (RV) diastolic collapse, excessive respiratory variation of left ventricular and RV filling velocities, and inferior vena cava plethora consistent with cardiac tamponade. In addition, a mass was seen in the pericardial space that infiltrated the RV free wall and extended into the RV cavity (Figure 1, Figure 2; Movies 1 and 2). Pericardiocentesis was performed and 620 mL of serosanguinous fluid was removed. Analysis revealed an inflammatory exudate with a predominance of polymorphonuclear leukocytes and reactive mesothelial cells. Cytology was negative for malignancy. Gram stain was negative and there was no growth on aerobic and anaerobic cultures.Figure 2Left parasternal right ventricular (RV) inflow view demonstrating pericardial mass (arrow) infiltrating RV free wall and resulting in large mobile RV intracardiac mass. RA, Right atrium.View Large Image Figure ViewerDownload (PPT)Malignancy was thought to be the likely diagnosis and a chest computed tomography scan was performed to identify the site of the primary tumor. This demonstrated a moderate-sized pericardial effusion with enhancement of the pericardium. A large mass was seen in the pericardial space with invasion of the anterior RV (Figure 3). The mass measured 3.3 × 4.7 × 2.9 cm. There were also multiple 5-mm nodules scattered throughout both lung fields and several small mediastinal lymph nodes (Figure 4). The findings were thought to be consistent with metastatic malignancy.Figure 3Chest computed tomography scan demonstrating moderate-sized pericardial effusion and large pericardial mass (arrow) infiltrating right ventricle (RV). LV, Left ventricle; RA, right atrium.View Large Image Figure ViewerDownload (PPT)Figure 4Chest computed tomography scan demonstrating multiple small intraparenchymal and pleural-based pulmonary nodules (arrows).View Large Image Figure ViewerDownload (PPT)A direct biopsy of the RV mass through the right internal jugular vein was performed under transthoracic echocardiography guidance. The biopsy specimens demonstrated mild myocardial interstitial fibrosis and there were small separate fragments demonstrating fibrinopurulent exudate. These contained fibrin, acute inflammatory cells, and colonies of filamentous bacteria with sulfur granules diagnostic of Actinomyces species (Figure 5). The bacteria were gram positive and silver and acid-fast stains were negative.Figure 5Light microscopy demonstrating irregular branched filaments diagnostic of Actinomycoses species (A). These bacteria were gram positive (B).View Large Image Figure ViewerDownload (PPT)The patient was treated with intravenous penicillin G (18 million units per day [MU]/d) in divided doses for 6 weeks, followed by 8 MU/d for a total of 6 months of therapy. Subsequent dental evaluation demonstrated poor dentition with evidence of advanced periodontal disease requiring multiple dental extractions. He became afebrile with therapy, his white blood cell count normalized, and his symptoms resolved. An echocardiogram 5 months after the initiation of therapy demonstrated complete resolution of the pericardial and RV mass with no evidence of pericardial effusion or constriction. He was asymptomatic at 1-year follow-up.DiscussionCardiac actinomycosis is a rare but potentially treatable disease entity.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar There have been two comprehensive reviews published previously in the literature.2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar In 1944, Cornell and Shookhoff2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar detailed 68 cases of cardiac actinomycosis documented between 1884 and 1944. A subsequent review by Fife et al4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar in 1991 described an additional 19 cases of pericardial actinomycosis between 1950 and 1991. Since this last publication, very few additional cases of cardiac actinomycosis have been reported.5O'Sullivan R.A. Armstrong J.G. Rivers J.T. Mitchell C.A. Pulmonary actinomycosis complicated by effusive constrictive pericarditis.Aust N Z J Med. 1991; 21: 879-880Crossref PubMed Scopus (13) Google Scholar, 6Zijlstra E.E. Swart G.R. Godfroy F.J. Degener J.E. Pericarditis, pneumonia and brain abscess due to a combined Actinomyces-Actinobacillus actinomycetemcomitans infection.J Infect. 1992; 25: 83-87Abstract Full Text PDF PubMed Scopus (48) Google Scholar, 7Garini G. Bordi C. Mazzi A. Savazzi G. Tosi C. Thoracic actinomycosis with lung, mediastinal, and pericardial involvement: a case report.Recenti Prog Med. 1995; 86: 107-111PubMed Google Scholar, 8van Mook W.N. Simonis F.S. Schneeberger P.M. van Opstal J.L. A rare case of disseminated actinomycosis caused by Actinomyces meyeri.Neth J Med. 1997; 51: 39-45Crossref PubMed Scopus (17) Google Scholar, 9Litwin K.A. Jadbabaie F. Villanueva M. Case of pleuropericardial disease caused by Actinomyces odontolyticus that resulted in cardiac tamponade.Clin Infect Dis. 1999; 29: 219-220Crossref PubMed Scopus (20) Google Scholar, 10Esposti D. Lippolis A. Cipolla M. Bonazzi M. An uncommon cause of pericardial actinomycosis.Ital Heart J. 2000; 1: 632-635PubMed Google Scholar, 11Shinagawa N. Yamaguchi E. Takahashi T. Nishimura M. Pulmonary actinomycosis followed by pericarditis and intractable pleuritis.Intern Med. 2002; 41: 319-322Crossref PubMed Scopus (11) Google Scholar, 12Janoskuti L. Lengyel M. Fenyvesi T. Cardiac actinomycosis in a patient presenting with acute cardiac tamponade and a mass mimicking pericardial tumor.Heart. 2004; 90: e27Crossref PubMed Scopus (12) Google Scholar, 13Makaryus A. Latzman J. Yang R. Rosman D. A rare case of Actinomyces israelli presenting as pericarditis in a 75 year old man.Cardiol Rev. 2005; 13: 125-127Crossref PubMed Scopus (10) Google Scholar, 14Lam S. Samraj J. Rahman S. Hilton E. Primary actinomycotic endocarditis: case report and review.Clin Infect Dis. 1993; 16: 481-485Crossref PubMed Scopus (31) Google Scholar, 15Reddy I. Ferguson Jr, D.A. Sarubbi F.A. Endocarditis due to Actinomyces pyogenes.Clin Infect Dis. 1997; 25: 1476-1477Crossref PubMed Scopus (18) Google Scholar, 16Huang K.L. Beutler S.M. Wang C. Endocarditis due to Actinomyces meyeri.Clin Infect Dis. 1998; 27: 909-910Crossref PubMed Scopus (16) Google Scholar, 17Mardis J.S. Many Jr, W.J. Endocarditis due to Actinomyces viscosus.South Med J. 2001; 94: 240-243PubMed Google Scholar, 18Westling K. Lidman C. Thalme A. Tricuspid valve endocarditis caused by a new species of Actinomyces: Actinomyces funkei.Scand J Infect Dis. 2002; 34: 206-207Crossref PubMed Scopus (25) Google Scholar, 19Julian K. Flesco L. Clarke L. Parent L. Actinomyces viscosus endocarditis requiring aortic valve replacement.J Infect. 2005; 50: 359-362Abstract Full Text Full Text PDF PubMed Scopus (19) Google ScholarActinomyces species are facultative anaerobic gram-positive bacilli that are part of the normal human flora and are commonly found in the oropharanx, bronchi, gastrointestinal tract, and female genital tract.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar Infections caused by Actinomyces species are rare and usually indolent, locally invasive processes involving the cervicofacial area.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar Infections involving the thorax (lungs, pleura, mediastinum, or chest wall), abdominopelvic region, and central nervous system are less common.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar Cardiac actinomycosis is an unusual form of thoracic involvement and usually manifests as pericardial disease, accounting for 70% to 80% of cardiac cases.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar, 3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Myocarditis and endocarditis are rarer manifestations.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar, 3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 14Lam S. Samraj J. Rahman S. Hilton E. Primary actinomycotic endocarditis: case report and review.Clin Infect Dis. 1993; 16: 481-485Crossref PubMed Scopus (31) Google Scholar, 15Reddy I. Ferguson Jr, D.A. Sarubbi F.A. Endocarditis due to Actinomyces pyogenes.Clin Infect Dis. 1997; 25: 1476-1477Crossref PubMed Scopus (18) Google Scholar, 16Huang K.L. Beutler S.M. Wang C. Endocarditis due to Actinomyces meyeri.Clin Infect Dis. 1998; 27: 909-910Crossref PubMed Scopus (16) Google Scholar, 17Mardis J.S. Many Jr, W.J. Endocarditis due to Actinomyces viscosus.South Med J. 2001; 94: 240-243PubMed Google Scholar, 18Westling K. Lidman C. Thalme A. Tricuspid valve endocarditis caused by a new species of Actinomyces: Actinomyces funkei.Scand J Infect Dis. 2002; 34: 206-207Crossref PubMed Scopus (25) Google Scholar, 19Julian K. Flesco L. Clarke L. Parent L. Actinomyces viscosus endocarditis requiring aortic valve replacement.J Infect. 2005; 50: 359-362Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar To our knowledge, this is the only reported case in which pericardial infection infiltrated the RV free wall resulting in a mobile RV intracavitary mass.Pericardial actinomycosis is most often the result of direct secondary spread from adjacent pulmonary disease.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar The majority of cases of pericardial actinomycosis have prior or concomitant pulmonary actinomycosis and the pericardium becomes infected by direct invasion. Twenty-three of the 29 reported cases (79%) of pericardial actinomycosis since 1950 (including this case) had documented thoracic involvement.4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar, 5O'Sullivan R.A. Armstrong J.G. Rivers J.T. Mitchell C.A. Pulmonary actinomycosis complicated by effusive constrictive pericarditis.Aust N Z J Med. 1991; 21: 879-880Crossref PubMed Scopus (13) Google Scholar, 6Zijlstra E.E. Swart G.R. Godfroy F.J. Degener J.E. Pericarditis, pneumonia and brain abscess due to a combined Actinomyces-Actinobacillus actinomycetemcomitans infection.J Infect. 1992; 25: 83-87Abstract Full Text PDF PubMed Scopus (48) Google Scholar, 7Garini G. Bordi C. Mazzi A. Savazzi G. Tosi C. Thoracic actinomycosis with lung, mediastinal, and pericardial involvement: a case report.Recenti Prog Med. 1995; 86: 107-111PubMed Google Scholar, 8van Mook W.N. Simonis F.S. Schneeberger P.M. van Opstal J.L. A rare case of disseminated actinomycosis caused by Actinomyces meyeri.Neth J Med. 1997; 51: 39-45Crossref PubMed Scopus (17) Google Scholar, 9Litwin K.A. Jadbabaie F. Villanueva M. Case of pleuropericardial disease caused by Actinomyces odontolyticus that resulted in cardiac tamponade.Clin Infect Dis. 1999; 29: 219-220Crossref PubMed Scopus (20) Google Scholar, 10Esposti D. Lippolis A. Cipolla M. Bonazzi M. An uncommon cause of pericardial actinomycosis.Ital Heart J. 2000; 1: 632-635PubMed Google Scholar, 11Shinagawa N. Yamaguchi E. Takahashi T. Nishimura M. Pulmonary actinomycosis followed by pericarditis and intractable pleuritis.Intern Med. 2002; 41: 319-322Crossref PubMed Scopus (11) Google Scholar, 12Janoskuti L. Lengyel M. Fenyvesi T. Cardiac actinomycosis in a patient presenting with acute cardiac tamponade and a mass mimicking pericardial tumor.Heart. 2004; 90: e27Crossref PubMed Scopus (12) Google Scholar, 13Makaryus A. Latzman J. Yang R. Rosman D. A rare case of Actinomyces israelli presenting as pericarditis in a 75 year old man.Cardiol Rev. 2005; 13: 125-127Crossref PubMed Scopus (10) Google Scholar Thus, thoracic actinomycosis appears to be the greatest risk factor for the development of pericardial actinomycosis. Periodontal disease may also be a risk factor as 26% of the 19 patients in the review by Fife et al4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar had periodontal disease.Cardiac actinomycosis with pericardial involvement often presents with insidious and nonspecific symptoms.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar The most common symptoms are dyspnea (68% of patients), cough (63%), chest pain (53%), and fever (53%).4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Common clinical findings include a pleural effusion (68%), tachypnea (63%), hepatomegaly (58%), peripheral edema (47%), and a cutaneous lesion or sinus tract (32%).4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Pericardial rubs have been reported in only a minority of patients (32%).3Dutton W.P. Inclan A.P. Cardiac actinomycosis.Chest. 1968; 54: 565-566Crossref Scopus (20) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Clinical evidence of cardiac tamponade is common during the disease course and occurred in 14 of the 29 patients (48%) described in the series of Fife et al4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar (19 patients), subsequent case reports (10 patients), and the current case.5O'Sullivan R.A. Armstrong J.G. Rivers J.T. Mitchell C.A. Pulmonary actinomycosis complicated by effusive constrictive pericarditis.Aust N Z J Med. 1991; 21: 879-880Crossref PubMed Scopus (13) Google Scholar, 6Zijlstra E.E. Swart G.R. Godfroy F.J. Degener J.E. Pericarditis, pneumonia and brain abscess due to a combined Actinomyces-Actinobacillus actinomycetemcomitans infection.J Infect. 1992; 25: 83-87Abstract Full Text PDF PubMed Scopus (48) Google Scholar, 7Garini G. Bordi C. Mazzi A. Savazzi G. Tosi C. Thoracic actinomycosis with lung, mediastinal, and pericardial involvement: a case report.Recenti Prog Med. 1995; 86: 107-111PubMed Google Scholar, 8van Mook W.N. Simonis F.S. Schneeberger P.M. van Opstal J.L. A rare case of disseminated actinomycosis caused by Actinomyces meyeri.Neth J Med. 1997; 51: 39-45Crossref PubMed Scopus (17) Google Scholar, 9Litwin K.A. Jadbabaie F. Villanueva M. Case of pleuropericardial disease caused by Actinomyces odontolyticus that resulted in cardiac tamponade.Clin Infect Dis. 1999; 29: 219-220Crossref PubMed Scopus (20) Google Scholar, 10Esposti D. Lippolis A. Cipolla M. Bonazzi M. An uncommon cause of pericardial actinomycosis.Ital Heart J. 2000; 1: 632-635PubMed Google Scholar, 11Shinagawa N. Yamaguchi E. Takahashi T. Nishimura M. Pulmonary actinomycosis followed by pericarditis and intractable pleuritis.Intern Med. 2002; 41: 319-322Crossref PubMed Scopus (11) Google Scholar, 12Janoskuti L. Lengyel M. Fenyvesi T. Cardiac actinomycosis in a patient presenting with acute cardiac tamponade and a mass mimicking pericardial tumor.Heart. 2004; 90: e27Crossref PubMed Scopus (12) Google Scholar, 13Makaryus A. Latzman J. Yang R. Rosman D. A rare case of Actinomyces israelli presenting as pericarditis in a 75 year old man.Cardiol Rev. 2005; 13: 125-127Crossref PubMed Scopus (10) Google Scholar Constrictive pericarditis was documented in 36% of patients.4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar, 5O'Sullivan R.A. Armstrong J.G. Rivers J.T. Mitchell C.A. Pulmonary actinomycosis complicated by effusive constrictive pericarditis.Aust N Z J Med. 1991; 21: 879-880Crossref PubMed Scopus (13) Google Scholar, 6Zijlstra E.E. Swart G.R. Godfroy F.J. Degener J.E. Pericarditis, pneumonia and brain abscess due to a combined Actinomyces-Actinobacillus actinomycetemcomitans infection.J Infect. 1992; 25: 83-87Abstract Full Text PDF PubMed Scopus (48) Google Scholar, 7Garini G. Bordi C. Mazzi A. Savazzi G. Tosi C. Thoracic actinomycosis with lung, mediastinal, and pericardial involvement: a case report.Recenti Prog Med. 1995; 86: 107-111PubMed Google Scholar, 8van Mook W.N. Simonis F.S. Schneeberger P.M. van Opstal J.L. A rare case of disseminated actinomycosis caused by Actinomyces meyeri.Neth J Med. 1997; 51: 39-45Crossref PubMed Scopus (17) Google Scholar, 9Litwin K.A. Jadbabaie F. Villanueva M. Case of pleuropericardial disease caused by Actinomyces odontolyticus that resulted in cardiac tamponade.Clin Infect Dis. 1999; 29: 219-220Crossref PubMed Scopus (20) Google Scholar, 11Shinagawa N. Yamaguchi E. Takahashi T. Nishimura M. Pulmonary actinomycosis followed by pericarditis and intractable pleuritis.Intern Med. 2002; 41: 319-322Crossref PubMed Scopus (11) Google Scholar, 12Janoskuti L. Lengyel M. Fenyvesi T. Cardiac actinomycosis in a patient presenting with acute cardiac tamponade and a mass mimicking pericardial tumor.Heart. 2004; 90: e27Crossref PubMed Scopus (12) Google Scholar, 13Makaryus A. Latzman J. Yang R. Rosman D. A rare case of Actinomyces israelli presenting as pericarditis in a 75 year old man.Cardiol Rev. 2005; 13: 125-127Crossref PubMed Scopus (10) Google Scholar Importantly, patients tend to present with an insidious process with the diagnosis made weeks to months after the initial onset of symptoms.4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar This is in direct contrast to the fulminant presentation of most other causes of purulent pericarditis.Digital clubbing was present in our patient and likely the result of his infection. Bilateral digital clubbing is associated with a number of chronic and subacute conditions including infectious diseases such as infective endocarditis,20Spicknall K.E. Zirwas M.J. English J.C. Clubbing: an update on diagnosis, differential diagnosis, pathophysiology, and clinical relevance.J Am Acad Dermatol. 2005; 52: 1020-1028Abstract Full Text Full Text PDF PubMed Scopus (110) Google Scholar and a previous report has described digital clubbing in a patient with endocarditis caused by Actinomyces viscosus.19Julian K. Flesco L. Clarke L. Parent L. Actinomyces viscosus endocarditis requiring aortic valve replacement.J Infect. 2005; 50: 359-362Abstract Full Text Full Text PDF PubMed Scopus (19) Google ScholarThe diagnosis of cardiac actinomycosis can be elusive. Routine laboratory tests are nonspecific and an elevated leukocyte count may be seen in only 63% of patients.4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Peripheral blood cultures are also almost always negative.2Cornell A. Shookhoff H.B. Actinomycosis of the heart simulating rheumatic fever: report of 3 cases with a review of the literature.Arch Intern Med. 1944; 74: 11-27Crossref Scopus (12) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Blood samples need to be collected and submitted using strict anaerobic technique, stimulation by a carbon dioxide–enriched environment may be necessary, and the growth of Actinomycoses species may be slow.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 21Rodloff A.C. Hillier S.L. Moncla B.J. Peptostreptococcus, Propionibacterium, Lactobacillus, Actinomyces, and other non-spore forming anaerobic gram-positive bacteria.in: Murray P.R. Baron E.J. Pfaller M.A. Manual of clinical microbiology. American Society of Microbiology, Washington (DC)1999: 672Google Scholar Pericardiocentesis often fails to secure the diagnosis. Purulent pericardial fluid with a predominance of polymorphonuclear leukocytes is present in 53% of patients,4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar however, this may occur with other causes of purulent pericarditis. The yield of pericardial fluid cultures has been reported to be low with Actinomyces species identified in only 22% of patients.4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Similarly, low yields (26%) have been observed for cultures of biopsy specimens.4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar The majority of diagnoses are made by histopathology with light microscopy identifying irregular branched gram-positive filaments associated with sulfur granules.1Smego R.A. Foglia G. Actinomycosis.Clin Infect Dis. 1998; 26: 1255-1261Crossref PubMed Scopus (413) Google Scholar, 4Fife T. Finegold S.M. Grennan T. Pericardial actinomycosis: case report and review.Rev Infect Dis. 1991; 13: 120-126Crossref PubMed Scopus (37) Google Scholar Our case again highlights the difficulty in making a diagnosis by culture alone as both peripheral blood and pericardial fluid cultures were negative.The good prognosis of patients with cardiac actinomycosis diagnosed premortem and treated with appropriate antibiotic therapy highlights the importance of making a correct diagnosis. In the available case reports since 1950, 86%