CT features of hepatic metastases from hepatoid adenocarcinoma

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Hepatoid adenocarcinoma (HAC) is a rare variant of adenocarcinoma.
• Hepatic metastases from HAC can present diagnostic challenges.
• Distinguishing HAC metastases from primary liver cancers like hepatocellular carcinoma (HCC) is crucial for treatment planning.

Purpose of the Study:

• To characterize the imaging presentation of hepatic metastases from hepatoid adenocarcinoma (HAC).
• To identify key computed tomography (CT) findings associated with HAC liver metastases.
• To compare imaging features of HAC liver metastases with known HCC imaging characteristics.

Main Methods:

• Retrospective analysis of 11 patients with confirmed HAC liver metastasis.
• Review of contrast-enhanced computed tomography (CT) scans, including arterial and portal venous phases.
• Consensus review by two radiologists assessing enhancement patterns, necrosis, venous thrombi, and overall diagnosis.

Main Results:

• Heterogeneous hyper-enhancement on arterial phase (63.6%) and heterogeneous hypo-enhancement on portal venous phase (81.8%) were common.
• Arterial phase hypo-enhancement was observed in 36.4% of cases.
• Venous thromboses occurred in 36.4% of patients.
• Overall imaging diagnoses included 'HCC-like' (63.6%), 'indeterminable' (9.1%), and 'HCC-unlike' (27.3%).

Conclusions:

• Hepatic metastases from HAC exhibit diverse imaging features on CT.
• A significant proportion of HAC liver metastases mimic HCC imaging features (arterial enhancement with venous washout).
• However, arterial phase hypo-enhancement, a feature distinct from typical HCC, is also frequently observed in HAC metastases.