Case 7

Pericardial Cyst

Epidemiology

Pericardial cysts are congenital lesions formed when pericardium is pinched off during development. Most pericardial cysts are located in the right cardiophrenic angle followed by the left cardiophrenic angle. Cysts can be readily distinguished from other cardiophrenic angle masses with cross-sectional imaging (either CT or MRI). Pericardial cysts are well-defined, nonenhancing lesions of fluid attenuation. They are uniformly hyperintense on T2-weighted MRI.

Presentation

Patients with pericardial cysts are usually asymptomatic, but large cysts can cause dyspnea, chest pain, cough, and rarely cardiac tamponade. Treatment of symptomatic lesions is surgical resection or percutaneous drainage.

Imaging

The chest radiograph shows a well-defined right cardiophrenic angle mass (Fig. A). Coronal CT scan (Fig. B) shows a mass with fluid attenuation and no perceptible wall. Axial T2-weighted MRI (Fig. C) confirms uniform high signal within the lesion.