A Rare Left Atrial Appendage Papillary Fibroelastoma

Papillary fibroelastoma (PFE) rarely arises in the left atrial appendage (LAA) and is often misidentified as intracardiac thrombus.

A 54-year-old female presented with 2 years of intermittent chest discomfort. She had no chronic illnesses and normal physical examinations. Transthoracic echocardiography, transesophageal echocardiography, and cardiac magnetic resonance identified a mass in the LAA. She underwent surgical resection of the mass together with partial LAA tissue. Intraoperative observation revealed a yellowish lesion at the LAA orifice. Pathologic examination showed a papillary architecture, confirming PFE.

Although benign, mobile LAA PFEs carry embolic risks and are easily misdiagnosed as thrombi.

This case underscores the vital role of multimodality imaging in preoperative diagnosis and suggests that PFE should be included in the differential diagnosis of LAA masses.