Discordant uptake of three different agents for liver scintigraphy in a patient with focal nodular hyperplasia

Focal nodular hyperplasia of the liver is composed of hepatocytes, variable amounts of Kupffer cells, and bile ducts. The amount of Kupffer cells per unit volume of tissue determines the uptake of Tc-99m phytate. However, the uptake of Tc-99m DTPA galactosyl human serum albumin (Tc-99m GSA) depends on the presence of normally functioning hepatocytes, and the uptake and excretion of Tc-99m pyridoxyledene-5-methyl tryptophen (Tc-99m PMT) depends on the presence of normally functioning hepatocytes as well as the patency of bile ducts. In this proven case of focal nodular hyperplasia, there was no uptake of Tc-99m phytate, but mildly decreased uptake of Tc-99m GSA and increased uptake of Tc-99m PMT were observed, compared to normal liver tissue. These are exceptional findings for focal nodular hyperplasia and mimicked those of a hepatic adenoma.