Primary and Secondary Vena Cava Tumors

Tumor Types

The most common primary tumor of the inferior vena cava (IVC) and superior vena cava (SVC) is leiomyosarcoma. Primary venous leiomyosarcoma involves the IVC in 60% of patients, with three fourths of those involving the suprarenal and infrarenal segments ( Figure 1 ). These tumors are polypoid or nodular, are firmly attached to the vessel wall, and show less intratumor hemorrhage or necrosis than other sarcomas. The most common growth pattern is intraluminal, but the tumor can grow through the vein wall into adjacent structures in advanced cases. Such biologic behavior makes it difficult to differentiate a primary venous leiomyosarcoma from other retroperitoneal sarcomas. Metastatic disease to the lung, liver, kidney, bone, pleura, or chest wall occurs in nearly one half of patients by the time diagnosis is made.

Secondary tumors involve the IVC more often than primary tumors. They can affect any segment of the vena cava, and they often infiltrate its wall ( Box 1 ). Some malignancies exhibit intraluminal tumor thrombus as part of their biologic behavior, with renal cell cancer being the most common. Such renal cell cancers tend to be large (>4.5 cm), and they more often involve the right kidney. Thrombus is isolated to the renal vein–caval confluence in 50%; another 40% have thrombus in the suprarenal IVC, and 10% have thrombus extending into the right heart.