The patient presented with macroscopic hematuria and right flank pain. These are two of the classic presentation triad of renal cell carcinoma, consisting of hematuria, flank pain and a palpable mass.

Correlated with the imaging findings, the patient was diagnosed with renal cell carcinoma. Radical nephrectomy was performed. Histopathology confirmed the diagnosis of renal cell carcinoma.

Tumor thrombus is classically associated with renal cell carcinoma. In some cases, it may be difficult to differentiate between a bland thrombus and a tumor thrombus in the renal vein on a non-contrast or venous phase CT, as both are seen as a filling defect in the renal vein. However, an arterial phase CT will show enhancement of a tumor thrombus due to neovascularization of the tumor, as in this case.