Malignant Liver Lesions

Abstract

The liver is a common site for both primary and metastatic malignant lesions. Although the metastatic lesions are the most common, primary malignancies like hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) have become increasingly more common in recent years in the United States [1]. HCC arises from the hepatic parenchymal cells, the hepatocytes, and CC from the cells lining the major bile ducts and gallbladder, the cholangiocytes. In Asian countries like China, Taiwan, and Japan, HCC is one of the three most common causes of death due to malignancy. HCC has a serum marker in the form of α-fetoprotein, and no such marker exists for CC. Gallium-67 citrate, which has been an imaging agent for HCC over the years, still remains popular in places where F-18 fluorodeoxyglucose (F-18 FDG) is not readily available. A filling defect on a radiocolloid liver scan (Fig. 12.1.1) associated with intense Ga-67 uptake (Fig. 12.1.2) and increased serum α-fetoprotein in a patient is more likely to be HCC than any other type of malignancy. F-18 FDG shows avidity for CC, HCC, metastatic lesions, and abscesses. Being a common imaging agent for many different types of liver lesions, F-18 FDG imaging provides no specificity for any one particular type of malignancy.