**Introduction/Hypothesis:**
Papillary fibroelastomas (PFE) have recently been identified as the most common benign cardiac tumors, often found on valvular surfaces, most commonly the aortic valve followed by the mitral valve. However, PFEs can also attach to extra-valvular structures, including the left atrial appendage (LAA) and its surroundings, although this is less common. An area of interest related to PFEs is the coumadin ridge, also known as the Q-tip, a unique anatomical ridge in the left atrium specifically between the LAA and the left upper pulmonary vein (LUPV). This area is associated with an increased risk of thrombus formation due to blood stasis, which is why it derives its name from the anticoagulant medication coumadin (warfarin) which is often used to reduce this risk.
LAA tumors can pose a diagnostic challenge due to their anatomical complexities. The coumadin ridge, despite being a normal anatomical structure, can be mistaken for a tumor or thrombus due to its shape and position. This can lead to unnecessary and costly treatments for patients. These neoplasms are best detected by transesophageal echocardiography (TEE), and despite their benign nature, they have been associated with a range of serious embolic events. Therefore, accurately identifying and categorizing a mass in this region is notably important for accurate management, and yet can be clinically challenging.

**Methods**
We describe 13 cases of pathology-proven PFEs located in the LAA, including seven cases specifically on the coumadin ridge. Patient data, including demographics, mass characteristics, diagnostic imaging, and histopathologic evaluations were collected and analyzed.

**Results**
Thirteen patients with pathology-proven PFEs in the LAA were included in the study, of which seven cases involved the coumadin ridge. The median age of the cohort is 73 (IQR 67-77), and 54% of the patients were male. Tumor sizes ranged from 2mm to 20mm, with a median of 5mm (IQR 3.5-8.5). Twelve (92.3%) of the PFEs were initially visualized on TEE, and one case was diagnosed postoperatively by pathologists after the excision of the LAA. The majority of cases were incidental diagnoses, with 46% of cases incidentally discovered intraoperatively by routine TEE, and 30% visualized on TEE done for diverse reasons including valvular assessment, exclusion of infective endocarditis, assessment of intra-cardiac source of embolism and coronary artery disease (CAD) assessment. One case was incidentally detected on cardiac magnetic resonance imaging (MRI) performed as part of a metastatic tumor workup. Four (30%) patients presented with symptoms of stroke/transient ischemic attack (TIA), of which two had a previous history of stroke. One patient had symptoms of both TIA and angina pectoris. Cardiovascular disease and atherosclerotic risk factors were prevalent: 69% had hyperlipidemia, 38% had atrial fibrillation (Afib) all of whom were therapeutically anticoagulated for at least 3 months pre-surgically, 31% had coronary artery disease (CAD), 54% had hypertension, and 46% were former smokers.

**Conclusion**
Masses in the LAA are rare, but when present, they can be significant intracardiac sources of embolism, leading to serious sequelae. Accurate identification and categorization of these masses are challenging, yet critical, to guide appropriate surgical intervention and improve patient outcomes. A rare LAA mass could be a PFE and can be difficult to distinguish from thrombus/clot. Therefore, clinicians, cardiologists and imagers should keep PFE of the LAA/coumadin ridge in mind when viewing masses in the LAA.



Pathologically Proven Papillary Fibroelastomas Attached to the Left Atrial Appendage 

This course will explore basic and cutting-edge imaging techniques to improve patient care and hone individual skills in performance and interpretation of echocardiography, nuclear cardiology, cardiac computed tomography, and cardiovascular magnetic resonance imaging. Days will reinforce how cardiovascular imaging may improve comprehension in ischemic heart disease, structural heart disease, cardiomyopathies, and heart failure. Experts will utilize novel techniques to reinforce key topics including taped interventional cases and a strong emphasis on case presentations.