Image Diagnosis: Pericardial Cyst

Abstract

A 50-year-old woman presented to the Emergency Department with 5 days of diffuse abdominal pain and constipation. An acute abdominal series was obtained to rule out a bowel obstruction during her workup. The upright chest image of the acute abdominal series demonstrated a smoothly rounded mass at the right cardiophrenic angle (Figure 1). This incidental finding was seen in more detail on her computed tomography scan of the abdomen and pelvis as a sharply demarcated, thin-walled, fluid-filled lesion measuring 7.7 cm in diameter (Figure 2). These radiographic findings were consistent with a large pericardial cyst. Pericardial cysts are rare, usually benign congenital anomalies.1,2 The vast majority are asymptomatic and are usually found incidentally on chest radiographs, computed tomography scans, magnetic resonance images, or echocardiography. They represent 6% of mediastinal masses and 33% of all mediastinal cysts.1 Large pericardial cysts may cause compression on adjacent structures and organs, resulting in dyspnea, chest pain, or persistent cough.3 There have been reports of cyst rupture, cardiac compression, atrial fibrillation, and even sudden cardiac death from these cysts, although these complications are uncommon.4,5 Recent case reports have shown that pericardial cysts can sometimes be confused with a coronary artery aneurysm, dextrocardia, malignancy, and even pneumonia.6–9 When surgery is required to remove them, video-assisted thoracoscopic surgery, thoracotomy, median sternotomy, and ultrasound-guided percutaneous aspiration have all been used with success.3 In this particular case, the patient was found to have colon cancer and a mass that was causing a bowel obstruction, independent of the pericardial cyst. A sigmoid colectomy was performed and the patient is undergoing further evaluation for the malignancy. The patient was asymptomatic from her pericardial cyst and nothing further was done from that standpoint. Figure 1. Upright chest x-ray from an abdominal series demonstrating a rounded mass at the right cardiophrenic angle. Figure 2. Computed tomography scan showing 7.7 cm pericardial cyst along the right heart boarder.