A case report of retroaortic left renal vein with tumor thrombus of renal cell carcinoma.

A 75-year-old woman was referred to our department for evaluation of a left renal tumor. Computed tomography and other imaging studies demonstrated a left renal mass and tumor extension into the left renal vein passing caudally behind the aorta. We clinically diagnosed the tumor as renal cell carcinoma (RCC) associated with a retroaortic left renal vein thrombus, and performed a radical nephrectomy. Pathological examination of the surgical specimen showed a grade 2, clear cell carcinoma with a renal vein thrombus and negative surgical margin. Retroaortic left renal vein is a rare anomaly with a prevalence of 1.8-2.4%. RCC associated with a retroaortic left renal vein thrombus is rarer still. To our knowledge, this is only the third case report to describe an RCC associated with a tumor thrombus in the retroaortic left renal vein.