Snapshot A 56-year-old man presents to his primary care physician for shortness of breath and episodes of lightheadedness. He says that his symptoms progressively worsened over the course of months. He recalls producing bloody sputum a few weeks ago and fainting for a few seconds yesterday night. Medical history is unremarkable. He denies alcohol, illicit drug, or cigarette use. Physical examination is remarkable for a "tumor plop" appreciated during diastole. An echocardiogram is performed and shows a left intra-atrial pedunculated mass. (Atrial myxoma) Introduction Cardiac tumors these can be divided into primary cardiac tumors myxoma (most common primary cardiac tumor) occur mainly in the left atrium rhabdomyoma metastatic tumors most common cardiac tumors overall primary cardiac tumors are extremely rare and are more likely to be benign Cardiac Tumors Cardiac Tumors Type Pathology Comment Myxoma Most commonly found in the atrium preferably in the fossa ovalis of the atrial septum Presentation Constitutional symptoms (fever, weight loss, and fatigue)commonly due to IL-6 production by the myxoma Can be friable and cause systemic embolization leading to stroke and other ischemic events Diastolic "plop" may be auscultated Masses can be pedunculated this mass can make its way towards the atrioventricular valve opening during systole, resulting in an obstruction (which can lead to syncope) and damaging the valve leaflets echocardiography will show pedunculated mass Histology complex structures surrounding blood vessels and may appear as cords, rings, nests, or poorly formed glands abundant mucopolysaccharide ground substance consists of chondroitin sulfate and hyaluronic acid consists of stellate or globular myxoma cells eosinophilic cytoplasm ill-defined cell borders oval nucleus indistinct nucleiopen chromatin Most common primary heart tumor in adults Echocardiography can identify the tumor Surgery is the definitive treatment Rhabdomyoma Approximately 50% of cases are associated with tuberous sclerosis Histology "spider cells" hamartomatous growths More common in pediatric patients and typically found within the first year of life