Pericardial lymphangioma: a rare benign albeit variably symptomatic tumefactive lesion.

Primary pericardial-based tumefactive lesions include pericardial cysts, mature teratomas, and lymphangiomas, and while benign they may result in clinical symptomatology that leads to their radiologic detection. We present the case of a 5-year-old boy with a heart murmur who was otherwise healthy and without significant medical history. Transthoracic echocardiogram, computed tomography, and magnetic resonance imaging studies revealed a pericardial multicystic mass imparting compression upon the right atrium and ventricle. The case proceeded to surgery in which complete resection of the mass was performed without complication, and the patient was discharged three days after. Pathology examination of the lesion determined it to be a pericardial lymphangioma with characteristic histologic features of sequestered vascular channels lined by endothelium that specifically expressed lymphatic-specific podoplanin (also known as D2-40), and with associated adipose tissue, smooth muscle bundles, and reactive lymphoid aggregates. Although a rare underlying etiology for mediastinal and specifically pericardial tumors, lymphangiomas should be considered in the differential of tumefactive lesions in this anatomic location.