Leiomyosarcoma of the pulmonary veins with extension to the left atrium.

A leiomyosarcoma of the right pulmonary vein in a 43-year-old woman extended to the right atrial wall and compromised the posterior mitral leaflet. Successful surgical treatment was accomplished with a right pneumonectomy, partial resection of the left atrial wall, and mitral valve replacement under cardiopulmonary bypass. Six months later a mediastinal recurrence with extension to the left hemithorax was treated with resection and postoperative radiotherapy.