Pericardial Cyst Causing RightVentricular Outflow TractObstructionArthur F. Ng, MD, and Jemi Olak, MD

Section of Thoracic Surgery, Department of Surgery,University of Chicago Hospitals, Pritzker School of Medicine,Chicago, Illinois

Pleuropericardial cysts are rare. Rarer still are cardiopul-monary complications caused by their presence. Wereport the case of a pericardial cyst producing high-graderight ventricular outflow tract obstruction and its subse-quent management. The clinical importance of trans-esophageal echocardiography is highlighted.

(Ann Thorac Surg 1997;63:1147–8)© 1997 by The Society of Thoracic Surgeons

Pleuropericardial cysts represent 5% to 7% of all me-diastinal tumors [1]. They are thought to result from

failure of fusion of one of the mesenchymal lacunae thatnormally fuse to form the pericardial sac and usuallycome to lie in the region of the anterior cardiophrenicangle. The natural history of the pericardial cyst isgenerally benign. Most authorities recommend its re-moval if diagnosis is in doubt or if symptoms are present.We report the case of a giant pericardial cyst that pro-duced right ventricular outflow tract obstruction and thatpresented as heart failure.

The patient is a 66-year-old man with a history ofhypertension who had generally been active and in goodhealth his entire life. Several months earlier he had notedintermittent chest discomfort that was unrelated to exer-tion. More recently, peripheral edema began to develop,and the patient was given increasing doses of diuretic.Due to the resistant nature of his edema, an echocardio-gram was performed. Notably, in 1982, a chest radio-graph identified mild cardiomegaly with extensive peri-cardial calcification. He had rheumatic fever as a child.He denied a history of tuberculosis, exposure to fungaldisease, radiation, or recent overseas travel.

On examination, he appeared in no distress. The bloodpressure was 150/70 mm Hg, and the heart rate was 80beats/min and regular. He was afebrile. There was nojugular venous distention. There was a grade 3/4 systolicejection murmur. The lungs were clear. The liver was ofnormal span. Bilateral 21 pitting pedal edema was noted.

Routine laboratory values were unremarkable. Anelectrocardiogram revealed a right bundle-branch blockwithout evidence of right ventricle hypertrophy. A chestradiograph showed extensive anterior pericardial calcifi-

cations, mild cardiomegaly, and no pulmonary vascularcongestion. Purified protein derivative of tuberculin test-ing was equivocal.

Transthoracic two-dimensional echocardiography showedan abnormal anterior mass compressing the right ven-tricular free wall. Transesophageal echocardiographydemonstrated the mass to be extrinsic, confined to thepericardium, and extending to compress the main pul-monary artery (Fig 1A). A 1 m/s outflow tract gradientwas demonstrated. No significant valvular abnormalitieswere identified. Magnetic resonance imaging demon-strated an irregular mass measuring 10 by 6 cm (Fig 2).Relative T1/T2 weighting revealed a complex mass ofmuscle density. As the mass was symptomatic and thediagnosis remained in question, the patient was referredfor operative exploration.

Administration of diuretics was discontinued and thepatient was hydrated overnight in preparation for theoperation. Transesophageal echocardiography and cen-tral venous pressure monitoring were employed. A car-diopulmonary perfusion team was placed on standby incase emergent cardiopulmonary bypass was required atinduction or to facilitate resection. The initial centralvenous pressure was 11 mm Hg and changed little afterinduction. A median sternotomy was performed. A large,calcified cyst occupying the anterior mediastinum wasencountered. Its anterior wall was approximately 5 mmthick and noncompliant. The cyst was unroofed and itscontents of 70 mL of necrotic debris were removed. Indoing so the right ventricular free wall was liberated andfine spicules of calcium were noted over the epicardialsurface. Transeosophogeal echocardiography revealedpersistent outflow obstruction near the pulmonary valveuntil more extensive cyst wall debridement was under-taken (Fig 1B). The central venous pressure, upon com-pletion of the resection, was 6 mm Hg. As the underlyingright ventricular free wall appeared to contract well, thecentral venous pressure had decreased after resection,and the pericardial calcifications were known to bechronic, the operation was concluded. The sternum wasclosed in the usual fashion. The patient had an unre-markable postoperative recovery and was discharged onpostoperative day 4.

Microbiologic stains and cultures were unremarkable.Hyphal forms were noted in a single culture bottle, butmycotic cultures failed to identify an organism. Histo-logic study revealed a fibrovascular cyst wall with evi-dence of chronic inflammation and extensive necrosismost consistent with a necrotic mesothelial cyst. Notablythere were no giant cells, granulomata, acid-fast bacilli,or fungi identified.

The patient was seen in follow-up approximately 1month after his discharge. At that time, he was well withno cardiac murmur on auscultation and near-completeresolution of his pedal edema. A follow-up transthoracicechocardiogram demonstrated no right ventricular out-flow tract obstruction and a mildly hypokinetic rightventricular free wall.

Accepted for publication Oct 30, 1996.

Address reprint requests to Dr Ng, Department of Surgery, CooperHospital/University Medical Center, 3 Cooper Plaza, Camden, NJ 08103.

1147Ann Thorac Surg CASE REPORT NG AND OLAK1997;63:1147–8 PERICARDIAL CYST CAUSING RVOTO

© 1997 by The Society of Thoracic Surgeons 0003-4975/97/$17.00Published by Elsevier Science Inc PII S0003-4975(97)00066-0

Comment

Although pericardial cysts are rare, they are the mostcommon benign pericardial tumor. The majority of suchcysts are discovered post mortem or as an incidentalfinding on routine chest radiograph. Most authorities donot favor their removal if the diagnosis can be reasonablyestablished by the classic position and configuration ofthe cyst.

A chest radiograph typically demonstrates the cystoccupying the anterior cardiophrenic angle, more oftenthe right than the left side. On the lateral projection, ateardrop configuration is seen as the cyst tends to con-form to the medial aspect of the pulmonary fissure.Needle aspiration of clear, watery fluid confirms thediagnosis. Resection is indicated if the diagnosis is indoubt, symptoms are present, or complications arise. Themost common presenting symptoms are vague chest

pain and dyspnea. Reported complications include car-diac compression [2, 3], cyst infection with or withoutcardiac erosion [4], and cyst rupture [5]. No cases ofmalignant degeneration have been reported.

This case serves to illustrate several important con-cerns regarding the management of such cysts. Themajority of pericardial cysts may be removed safelywithout the use of cardiopulmonary bypass. However,cardiopulmonary bypass should be available on standby,especially if there is concern that cardiac compressionmay render the induction of anesthesia potentiallytreacherous, if erosion of the right ventricular free wallhas taken place, or if resection will require extensivecardiac manipulation. Magnetic resonance imaging al-lowed characterization of cyst contents and established aplane between the cyst and the epicardium. Transesoph-ageal echocardiography allowed preoperative quantifica-tion of hemodynamic compromise. Moreover, trans-esophageal echocardiography helped to guide the extentof resection and to document the relief of obstruction.

References

1. McAllister HA Jr. Primary tumors and cysts of the heart andpericardium. Curr Probl Cardiol 1979;4:1–51.

2. Shaver VC, Bailey WR, Marrangoni AG. Acquired pulmonicstenosis due to external cardiac compression. Am J Cardiol1965;16:256–61.

3. Koch PC, Kronzon I, Winer HE, Adams P, Trubek M. Dis-placement of the heart by a giant mediastinal cyst. Am JCardiol 1977;40:445–8.

4. Chopra PS, Duke DJ, Pellet JR, Rahko PS. Pericardial cyst withpartial erosion of the right ventricular wall. Ann Thorac Surg1991;51:840–1.

5. King JT, Crosby I, Pugh D, Reed W. Rupture of a pericardialcyst. Chest 1971;60:611–2.

Fig 1. Long-axis view on transesophageal echocardi-ography demonstrates the right ventricular (RV) out-flow tract (A) before (arrow) and (B) after (arrow-head) pericardial cyst resection. Transesophagealechocardiography was used preoperatively and in-traoperatively. (AO 5 aorta; LA 5 left atrium; LV5 left ventricle; PA 5 pulmonary artery.)

Fig 2. In cross-section, magnetic resonance imaging demonstrates awell-delineated mass anterior to the right ventricle (arrow).

1148 CASE REPORT NG AND OLAK Ann Thorac SurgPERICARDIAL CYST CAUSING RVOTO 1997;63:1147–8