The authors describe four cases of uncommon surgical findings in patients with the diagnosis of cardiac myxoma. In the first patient an encapsulated tumourous growth in the left atrium was present which was in the mural annulus of the mitral valve and in the adjacent parts of the atrial and ventricular wall and was evaluated from the histological aspect as annular sclerosis. In the second patient a tumour-like thrombus was detected in the right atrium which had the shape of a basket handle and was attached by two stalks to the atrial septum. The third patient had a myxoma of the left atrium covering a concurrent defect of the interatrial septum and the fourth patient had a large myxoma in the left atrium with three calcified small tumours in the area of the mural annulus of the mitral valve.

1st Surgical Clinic 1st Medical Faculty Charles University