Renal spindle cell tumor with thrombus extension into the inferior vena cava and the right atrium depicted by positron emission tomography/computerized tomography scan

Abstract

Tumor thrombus (also called intravascular tumor extension) can be defined as tumor extending into the vessel, typically a vein; it occurs in a lot of malignancies such as hepatocellular carcinoma and Wilms tumor. Tumor thrombus has been reported to demonstrate increase in fluorodeoxyglucose (FDG) uptake that would differentiate it from the benign bland thrombus, which would not take up FDG on positron emission tomography/computerized tomography (PET/CT) scan. We present a case of spindle cell sarcoma of the right kidney whose baseline contrast-enhanced CT revealed a mass replacing the right kidney and right renal vein and associated with thrombus in the inferior vena cava (IVC). Fluorine-18 FDG PET/CT imaging was done and revealed an FDG-avid hypermetabolic malignant right renal mass with hypermetabolic IVC thrombus extending to the right atrium.