A rare case of renal cell carcinoma with venous tumor thrombus involving lumbar vein

The incidence of renal cell carcinoma (RCC) is around 3% of all cancers. Venous tumor thrombus (VTT) formation and migration are unique aspects of RCC with an incidence of 4%–10%. Venous extension into the renal vein, inferior vena cava, and cardiac extension have been well documented in RCC. Various surgical approaches, including a cardiopulmonary bypass for tumor embolus extraction, may be needed. However, VTT extending into the lumbar vein at the initial presentation is very rare. We hereby report such rarity of RCC presentation of VTT involving renal vein and lumbar vein in a 50-year-old male.