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