Malignant clinical behavior of cardiac myxomas and "myxoid imitators".

The clinical experience with cardiac myxomas and "myxoid imitators" at the Humana Heart Institute International is reviewed and contrasted with a comprehensive review of the world literature. Twenty-two patients with primary cardiac tumors have been treated at our institution. Three (13.6%) of them had myxoid imitators, and 19 had classic myxomas. One of the 19 patients with a classic myxoma had recurrence on two occasions (recurrence rate, 5.3%). The cases of 57 patients from the world literature are reviewed. Recurrence and/or metastases (including formation of mycotic aneurysm) occurred in approximately 50% of these patients. The overall mortality in these patients was 47%. This review provides documentation of the malignant clinical behavior of cardiac myxomas and myxoid imitators. Neither local recurrence nor regrowth of the tumor in a new location, whether intracardiac or extracardiac, can be predicted from the microscopic appearance of the primary tumor. Resection of the myxoma with a wide margin is the recommended surgical procedure but does not ensure a cure. Therefore, long-term follow-up is mandatory.