Fossa Ovalis, An Unusual Localization of Mural Infective Endocarditis: Sometimes It is What It Seems! Case Report and Literature Review

Infective endocarditis (IE) is an uncommon disease, however still associated with high mortality. The complexity of the disease is due to various clinical manifestations as well as possible localizations of the disease, in both extracardiac and cardiac localizations. In most cases, IE involves cardiac valvular tissue or prosthetic material, but in rare cases vegetations can be found in special localizations. We present the case of a 56 years old male, hospitalized in our Infectious Disease Hospital for long-lasting fever. Initial transthoracic examination was negative but, due to high clinical suspicion, we performed a transesophageal examination with the evidence of aortic valve infection and a mass adherent to right side of fossa ovalis. Multi-imaging approach and anatomopathological examination led to the diagnosis of IE involving native aortic valve and fossa ovalis. The evidence of a mass at the level of interatrial septum is a rare finding, especially if right side is involved. The most important differential diagnosis in this case is between vegetation, thrombus or tumoral tissue. We performed a literature review of this rare presentation.