Highly Mobile Papillary Fibroelastoma Arising from a Left Ventricular False Tendon

A 66-year-old man with prostate cancer underwent contrast-enhanced computed tomography for cancer staging; the imaging incidentally revealed a 10 mm left ventricular mass. Transthoracic echocardiography demonstrated a highly mobile, pedunculated mass attached to a left ventricular false tendon. Cardiac magnetic resonance imaging was insufficient to characterise the tissue because of the extreme mobility of the lesion. Because of the left-sided location, pronounced mobility, and potential embolic risk, the tumour was excised en bloc with the attached false tendon via a transmitral approach through a left atriotomy, thereby avoiding a ventriculotomy. Histopathological examination confirmed a papillary fibroelastoma (PFE). This case highlights that PFEs associated with a left ventricular false tendon, although rare, should be considered in the differential diagnosis of highly mobile left ventricular masses; furthermore, a transmitral approach may provide safe access when the tumour is located on the apicoseptal aspect of the left ventricle.