Presentation
Vague abdominal pain.
Patient Data
Heterogeneously enhancing mass arising from the rightward aspect of the infrahepatic segment of the IVC and invading into it. Occlusion of right renal vein with retroperitoneal varices. Mass effect without invasion into other adjacent structures (liver, right kidney, duodenum, pancreatic head). Right adrenal is normal.
Case Discussion
Pathology from CT-guided biopsy: leiomyosarcoma.
Primary inferior vena cava leiomyosarcoma is a rare malignant mesenchymal tumor which begins in the vessel wall and can have both extraluminal and intraluminal components. The largest portion of the mass is outside of the vessel wall, with tumor thrombus filling and nearly occluding the inferior vena cava.
While this is a rare diagnosis, in this case, you can be fairly certain that you are dealing with a primary neoplasm of the inferior vena cava because that is the only structure into which the mass invades. It contacts the liver, right kidney, duodenum, and pancreas, but does not invade into these structures.
The major differential item to rule out is adrenocortical carcinoma, which frequently invades into the inferior vena cava (the right adrenal is normal).