Abstract: | We describe a patient with long-standing rheumatic mitral valve disease, left atrial dilatation, and a precommissurotomy history of left atrial thrombus. Following operation she was maintained on daily aspirin as an antithrombotic measure. For 6 years she had no evidence, echocardiographically, of left atrial thrombus. She underwent surgery for apparently nonmetastatic breast cancer in early 1986. In May 1986 the left atrium was echocardiographically clear. At approximately the same time, recurrence was found at the suture line. In October 1987, two metastatic lung lesions and a very large left atrial mass were detected by computed tomography. The atrial mass was surgically removed and found to be a thrombus. There was a striking temporal correlation between dissemination of carcinoma and development of a massive atrial thrombus. |