Figure 1. In the segment VII of the liver, there is a large, hypodense lesion which is hypermetabolic (SUVmax 8).

Figure 2. Large hypermetabolic intrahepatic lesion.

Intrahepatic cholangiocarcinoma is a malignancy arising from the intrahepatic bile ducts, which may infiltrate along the ducts or form a large nodule. There are a number of risk factors for cholangiocarcinoma, including: primary sclerosing cholangitis; congenital bile duct anomalies (particularly Caroli’s disease and choledochal cysts); exposure to Thorotrast (used in the past for biliary imaging); and, particularly in Asia where the incidence is higher, chronic biliary tract infection by the liver fluke Opisthorchis sinesis (particularly in Asia). Pathologically, these neoplasms are usually markedly desmoplastic and not bile-stained. Surgery currently offers the only chance for long-term survival and cure.

PET/CT adds metabolic information to the anatomic information provided by standard imaging modalities such as CT and MRI. Sensitivity of PET/CT is higher for intrahepatic (>90%) than for extrahepatic cholangiocarcinoma (60%). It is reliable for detecting distant metastasis (94%) but unreliable for assessing locoregional nodal metastasis (12%). PET/CT has been shown to detect previously unsuspected metastases (based on standard work-up, including contrast-enhanced CT), leading to a change in management in up to 17%. Thus PET/CT is recommended in the preoperative staging of intrahepatic and extrahepatic cholangiocarcinoma.