Hepatic lesion differentiated from accessory spleen by a heat-damaged red blood cell scan.

A 34-year-old woman referred for evaluation of an abdominal mass underwent a computed tomographic portagram that showed a large mass in the region of the left hepatic lobe and adjacent to the spleen. A liver-spleen scan with sulfur colloid did not clearly show whether the mass originated in the liver or the spleen. To evaluate the possibility of an accessory spleen, a selective spleen scan using Tc-99m-labeled heat-damaged red blood cells was performed and showed intense uptake in the region of the spleen only. The patient underwent surgical exploration and excision of the lesion, which proved to be focal nodular hyperplasia of the liver. Thus, the heat-damaged red blood cell scan ruled out an accessory spleen as a cause for the mass.