The atrial mass without an auscultatory "plop": renal cell carcinoma presenting with cardiac syncope-a case report.

Background: Renal cell carcinoma (RCC) presenting with extension of tumor thrombus into the inferior vena cava (IVC) and right atrium is a rare, life-threatening condition that requires surgical treatment with the simultaneous involvement of multiple surgical subspecialties. Case Description: We present a case of a 65-year-old male who presented to the hospital with syncope, and was subsequently diagnosed with a level four cavoatrial sinus tumor thrombus extending from a primary renal mass. The patient had no concerning physical exam and electrocardiogram (EKG) findings, however, transthoracic and transesophageal echocardiography revealed severely reduced systolic function with a hyperechoic, vascular, and cystic mass extending from the IVC into the right atrial cavity that originated from a renal mass that involved the right renal vein and IVC. Conclusions: The purpose of this case is to highlight the critical importance of early recognition and timely intervention in patients who present with nonspecific symptoms, such as syncope, which may signal underlying fatal conditions. This case illustrates RCC with tumor thrombus extending into the IVC and right atrium. This rare but serious manifestation highlights the need for a high index of suspicion and comprehensive evaluation when faced with vague clinical presentations. Early recognition not only facilitates appropriate management but can also alter the patient's prognosis and survival outcomes.