A 30-year-old man reported dysphagia and weight loss (15 kg) during the previous four months. Palpitations and chest pain unrelated to physical or emotional stress began two months later. A routine annual visit to the occupational medicine clinic revealed normal physical examination and laboratory tests. The chest X-ray (Figure 1A) suggested a diagnosis of dextrocardia that was not observed on previous annual chest X-rays, and the ECG (Figure 1B) was normal. Outpatient echocardiography was also normal. The patient was referred to the cardiology department for further investigation.

Figure 1.

(A) Chest X-ray showing pericardial cyst projecting into the right costophrenic angle mimicking dextrocardia; (B) ECG without abnormalities suggesting dextrocardia.

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Computed tomography (CT) scan (Figure 2) showed a large well-defined mass 11.2 cm × 7.4 cm in diameter projecting into the right costophrenic angle, suggesting a diagnosis of pericardial cyst or bronchogenic cyst.

Figure 2.

Large mass (*) in the right costophrenic angle on CT scan.

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Echocardiography (Figure 3) was repeated and revealed an echo-free structure containing a septum, pushing on the right atrium and visualized only from subcostal view, which showed a large pericardial cyst, and no other abnormal findings.

Figure 3.

Echocardiography, subcostal view, with a 87 mm × 88 mm mass containing a septum, suggesting a diagnosis of large pericardial cyst.

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Magnetic resonance imaging (MRI) (Figure 4) identified a non-enhanced, well-defined bilobed mass in the right costophrenic angle containing clear fluid with a volume of 70.4 ml, compatible with a giant pericardial cyst.

Figure 4.

Magnetic resonance image showing a bilobed mass (*) containing clear fluid in the right costophrenic angle.

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The patient underwent surgical excision of the mass (Figure 5) without complications. Histological examination confirmed the diagnosis of pericardial cyst. After three months of follow-up, he was symptom-free and the chest X-ray (Figure 6) showed no signs of dextrocardia.

Figure 5.

Pericardial cyst after excision.

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Figure 6.

Chest X-ray three months after surgery.

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Pericardial cysts are rare benign structures, most frequently located in the right costophrenic angle, but may also appear in the left costophrenic angle, hilum and superior mediastinum. They may be unilocular or multilocular with diameters ranging between 1 and 5 cm.1 In our case the pericardial cyst was very large, almost 9 cm in diameter, which makes it even more rare. The incidence of pericardial cysts is 1:100000 and they represent 6–7% of total mediastinal masses.2 They must be differentiated from cardiac chamber enlargement, diaphragmatic hernia, malignant tumors and bronchogenic cysts.

Pericardial cysts are usually asymptomatic and discovered incidentally on chest X-ray or echocardiography,3 while MRI and CT can differentiate between pericardial cyst and other solid mediastinal masses.1,2 The former appears as a thin-walled, well-defined mass filled with clear fluid without intravenous contrast enhancement.

Giant pericardial cysts may cause chest pain, dyspnea and cough secondary to airway compression. They may produce symptoms mimicking tricuspid stenosis, pulmonary stenosis or constrictive pericarditis.4 Atrial fibrillation,5 cardiac tamponade6 and even sudden death after a stress test7 have been reported. To the best of our knowledge, symptoms of dysphagia and significant weight loss, as in our case, have not previously been reported.

Treatment for symptomatic patients with large cysts includes surgical excision or percutaneous aspiration and alcohol sclerosing injection to prevent recurrence. Asymptomatic patients should be followed to monitor for possible future symptoms.

The authors have no conflicts of interest to declare.