Histology, Natural History, and Biology:
PFE is composed of connective tissue rich papillary fronds, covered by hyperplastic endothelium.1 Papillary fronds provide the tumor with the classical “sea anemone” appearance (Images 1 and 2). Tumor location is predominantly left sided and valvular: aortic valve is the most common location, followed by mitral valve.8, 10, 11 The left ventricle is the most commonly affected non-valvular site.12
PFE cause is unclear. There are multiple theories regarding tumor origination: microthrombi organization and consolidation, prior cardiac surgery or irridation,13 and viral exposure.14 Genomic analysis suggests these tumors demonstrate KRAS oncogene mutation.15