Papillary fibroelastoma of mitral valve

Gross and microscopic pathology of a papillary fibroelastoma of the mitral valve. The gross specimen (left) reveals multiple frond-like structures when photographed underwater. Low (right, top) and high power (right, bottom) microscopic features include dense elastin (black) at the core of each frond coated with collagen (red pink) and lined by flat endocardial cells.