Left atrial metastasis of renal cell carcinoma: a case report and review of the literature.

Background: Cardiac metastasis of renal cell carcinoma is an exceptional event, particularly when there is lack of inferior vena cava involvement. Indeed, only a few cases have been reported worldwide thus far. Moreover, discussion of treatment and follow-up strategies for cardiac metastasis of renal cell carcinoma is important because of the high risk of sudden death.
Case Presentation: We report the case of a 75-year-old Japanese man with metastatic tumor in the left atrium from renal cell carcinoma. He had a history of right renal cell carcinoma, for which he had undergone hand-assisted laparoscopic nephrectomy. Lung and bone metastases were detected after nephrectomy, and treatment with interferon-alpha was initiated. After disease progression, he was treated concurrently with targeted molecular therapy and radiotherapy for bone metastasis. After these therapies, a 42 × 24 mm mass was found on transthoracic echocardiography in left atrium without involvement of the right atrium or inferior vena cava. The provisional diagnosis was metastatic mass or myxoma, and surgical resection was performed. Histopathological examination led to a final diagnosis of metastatic tumor from clear cell renal cell carcinoma.
Conclusion: Cardiac metastasis, metastasis to the left atrium in particular, is rare in patients with renal cell carcinoma. In our study, surgery of the cardiac mass was effective to avoid sudden death and quality of life decline resulting from heart failure. We describe this case and review cardiac metastasis of renal cell carcinoma.