Kidney tumour mimicking cardiac mass

Area of Science:

• Cardiology
• Oncology
• Radiology

Background:

• Right atrial masses necessitate a differential diagnosis including cardiac tumors, extracardiac invasion, valvular vegetations, and thrombi.
• Myxoma is the most common primary cardiac tumor, often presenting as a right atrial mass.

Observation:

• A patient presented with a suspected cardiac tumor based on echocardiography revealing a right atrial mass.
• Further imaging with transesophageal echocardiography and magnetic resonance imaging identified the mass as extracardiac in origin.
• The mass was traced to a renal carcinoma with extension through the inferior vena cava into the right atrium.

Findings:

• Renal carcinoma extension to the right atrium via the inferior vena cava is an exceptionally rare presentation.
• Tumor extension with vena cava thrombosis is a known complication of renal carcinoma, but rarely reaches the atrium.
• The diagnosis was incidental in an asymptomatic patient, underscoring the value of advanced imaging.

Implications:

• This case expands the differential diagnosis for right atrial masses, emphasizing extracardiac sources.
• It highlights the utility of advanced imaging modalities in characterizing cardiac and vascular abnormalities.
• Clinicians should consider rare metastatic pathways when evaluating intracardiac findings, even in asymptomatic individuals.