A rare case of renal cell carcinoma with hematogenous extension into the right atrium discovered incidentally on echocardiogram

While hematogenous spread of renal cell carcinoma (RCC) is common, isolated extension into the renal vein and inferior vena cava (IVC) is rare and extension to the right atrium is even less likely. In the case, a 62-year-old Hispanic female was admitted for a suspected inferior myocardial infarction, and her echocardiogram revealed a right atrial mass consistent with the appearance of an atrial myxoma. Following cardiac catheterization, a histopathological examination of the mass revealed a clear cell tumor consistent with metastatic clear cell RCC. Following a CABG with excision of the atrial mas, the CT demonstrated a 5 cm right lower pole renal mass with hilar involvement, as well as filling defects in the IVC extending into the right renal vein; these findings were consistent with RCC tumor thrombus extension into the renal vein, IVC, and right atrium. The radical nephrectomy necessary for tumor removal could not be performed at this hospital, so the patient was discharged to a higher level of care. The incidence rate for RCC with extension into the right atrium is quite low, but clinicians should understand the lethality of RCC warrants immediate clinical investigation upon diagnosis. The increased utilization of sophisticated imaging modalities will likely continue to increase the rate of incidental discovery of such neoplasms, and physicians should keep RCC on the differential when a right atrial mass is discovered incidentally on echocardiogram.