Atrial myxoma. Gross specimen of an atrial myxoma, a benign, jelly-like tumour of the connective tissue found in the heart. These tumours are more commonly found under the skin where they can grow very large. A myxoma is rarely found in the heart, however here it can lead to the formation of blood clots and obstruct blood flow through the heart. This tumour was removed from the left atrium. An atrial myxoma causes symptoms of fever, pain in the joints & may provoke a sudden loss of consciousness if the flow of blood becomes obstructed.