Distant metastasis of renal adenocarcinoma in patients with a tumor thrombus in the renal vein and/or vena cava.

Autopsy records of renal adenocarcinoma cases were analyzed to investigate the mode of metastatic spread in instances of a tumor thrombus in the renal vein and/or vena cava. In this series of 1,828 cases 137 (7.5 per cent) had a tumor thrombus. Analysis revealed no significant differences in the incidence of the tumor thrombus between sexes or sides of primary renal involvement, or whether nephrectomy had been performed. The cases with a tumor thrombus showed higher frequencies of metastases in the liver, hepatic hilar lymph nodes and ureter, while metastases in the bones, contralateral kidney and brain were less frequent. The results suggest that bypass routes or lymphogenous spread of the tumor might be facilitated in some cases with a tumor thrombus.