Pericardial Cyst: An Uncommon Cause of Fever.

Pericardial cysts are a rare and benign entity that comprise 7% of the mediastinal masses. They are asymptomatic in over half of the cases, being usually detected as an incidental mass lesion on chest X-ray. When symptomatic, they usually present with dyspnea, chest pain, or persistent cough. Fever at presentation is an uncommon symptom. We present the case of a 40-year-old woman with a history of fever of unknown origin for over two years. The diagnostic study was relevant for an echocardiogram showing a pericardial cyst in the right cardiophrenic angle. While waiting for surgical resection, the patient developed heart failure refractory to diuretic therapy. Surgical resection of the cyst resulted in the resolution of her complaints with no further episodes of fever.