Breast and lung cancers, lymphoma, and malignant melanoma are frequent tumors associated with cardiac metastasis.[1] Cardiac metastasis is detected often at autopsy series,[2] which was found 10.7% in autopsies of 1029 cancer patients.[3] Myocardial metastasis is seen in 2% to 20% of all metastatic cancers. The pericardium is the most common metastatic location.
We report a patient in whom a large metastatic intramyocardial hypernephroma was incidentally detected during coronary bypass operation for coronary artery disease. To our knowledge, a large intramyocardial metastatic tumor from renal cell carcinoma that invaded almost completely the posterior segment of the left ventricle has hitherto been unreported.
During coronary bypass operation for the LAD, Cx, and RCA, an intramyocardial mass was observed that spread through the posterior segment of the left ventricle. The mass was very stiff and 6x8 cm in size, causing an upward shift in the acute margin of the right ventricle. It was difficult to distinguish its margins from the normal myocardial tissue. Resection of the mass was not performed and a biopsy specimen was taken, which then showed metastasis from hypernephroma. He was weaned from cardiopulmonary bypass easily and was discharged on the ninth postoperative day. No further treatment for cancer was considered. The patient was asymptomatic within the first postoperative year, and laboratory findings were normal for renal and cardiac functions. Thorax computed tomography showed a right pleural effusion and small-sized lung metastasis in the second postoperative year, but no further cardiac metastasis could be determined other than the preexisting large mass and collateral arteriovenous malformation detected by angiography (Fig. 1b).
There are no specific clinical symptoms and laboratory findings for cardiac metastases in cancer patients. Electrocardiographic changes are nonspecific; arrhythmias, low voltage complexes, nonspecific ST-T-segment modifications may occur. Occasionally, cardiac metastasis may imitate myocardial infarction with ST-segment elevation.[5,6] The incidence of supraventricular arrhythmias is higher in cancer patients with cardiac metastasis.[2] The onset of a murmur, pericardial pain or rub, effusion, arrhythmia, or ECG changes in a patient with a previous diagnosis of a malignancy should arouse suspicion of a cardiac metastasis. The tumor was unresectable in our case, but fortunately the patient was asymptomatic and could be weaned from coronary bypass operation.
Cardiac metastasis can affect the surgical approach, technique, and the extensiveness of surgery. These metastatic masses may be resected by cardiopulmonary bypass to prevent pulmonary emboli and circulatory disturbances. However, the effect of cardiopulmonary bypass on tumor extension and the outcome is not known. Polascik et al.[7] showed that five-year survival rates were nearly the same in cases of hypernephroma with only intracaval extension or right atrial invasion, both being below 5%. In case of disseminated metastatic disease involving the heart and great vessels, coronary artery revascularization methods may be modified. A high risk for mortality may exclude surgical revascularization and nonsurgical myocardial revascularization techniques can be used. Thorax computed tomography may not be helpful to determine metastasis from hypernephroma.
Asymptomatic patients with a diagnosis of a previous malignancy should be investigated more extensively with respect to metastasis to the heart and other vital organs.
1) Hall RJ, Cooley DA, McAllister HA Jr, Frazier OH. Neoplastic heart disease. In: Schlant RC, Alexander RW, editors. Hursts the heart, arteries and veins. 8th ed. New York: McGraw-Hill; 1994. p. 2007-29.
2) Tamura A, Matsubara O, Yoshimura N, Kasuga T, Akagawa S, Aoki N. Cardiac metastasis of lung cancer. A study of metastatic pathways and clinical manifestations. Cancer 1992; 70:437-42.
3) Klatt EC, Heitz DR. Cardiac metastases. Cancer 1990;65: 1456-9.
4) Bradley SM, Bolling SF. Late renal cell carcinoma metastasis to the left ventricular outflow tract. Ann Thorac Surg 1995;60:204-6.
5) Astorri E, Bonetti A, Fiorina P. ECG mimicking acute myocardial infarction during heart involvement by lung neoplasm. Int J Cardiol 2000;74:225-6.