Uptake of Tc-99m MAA by the liver during a thromboscintigram/lung scan

A young man with a swollen left leg was referred to us for a thromboscintigram/lung scan. The unexpected visualization of the liver during the flow study after intravenous injection of Tc-99m MAA into the dorsal veins of both feet provided the clue to his underlying problem. He was shown to have extensive venous collateralization in the left pelvis, and to a lesser degree on the right, due to a large pelvic mass. This was shown to consist of metastases from a previously treated testicular carcinoma. Venous drainage from the legs was shunted into the mesenteric circulation, which them emptied into the portal vein, thereby carrying the radiopharmaceutical to the liver. No uptake was seen in the spleen.