Abstract 14217: Needs Must: A Not-So Benign Pericardial Cyst

Abstract

Mrs. Z is a 56-year-old woman with a long history of symptomatic paroxysmal supraventricular tachycardia (PSVT) who presented with neck and back pain. MRI of cervical and thoracic spine revealed an abnormal signal in the right mediastinal area. A chest CT demonstrated a lobulated 5.8 x 5.5 x 3.5 cm, fluid density lesion contiguous with the pericardium adjacent to right atrium (RA) and inferior venacava (IVC) without wall thickening or solid components, consistent with a pericardial cyst (PC). A transthoracic echo (Panel B) revealed normal left ventricular size and systolic function with an EF of 66%. An echolucency adjacent to the RA and IVC consistent with a pericardial cyst was noted without any extrinsic compression. Given her asymptomatic presentation and normal cardiac imaging, a shared decision was made to conservatively manage.Two years ago, she underwent ablation for AVNRT, followed by an ablation for atrial tachycardia (AT). She continues to have short, symptomatic runs of AT ( Panel A ). A recent CMR re-demonstrated a large, septated pericardial cyst (6.2 x 5 cm) abutting the RA and IVC ( Panel C ). Given her on-going symptomatic SVT, she is referred for robotically assisted thoracoscopic surgery despite stability in size. Discussion: PCs are rare but typically benign. They are the third most common and account for 6% of mediastinal masses. They can be congenital or acquired, simple or complex, and have a predilection for R costophrenic angle (50-70%) followed by the L costophrenic angle (28-38%). Although most are asymptomatic and diagnosed incidentally, they sometimes can result in symptoms such as chest pain, dyspnea, and paroxysmal tachyarrhythmias. Large PCs can lead to tamponade. If a PC is suspected by CXR or echo, cardiac CT or CMR are used for confirmation. Periodic imaging is recommended every 1-2 yr. Most PCs resolve spontaneously. Treatment options include aspiration or surgical resection. Minimally invasive surgical options appear to be the best.