American Board of Surgery Qualifying Exam (ABS QE) Practice Test

How does HCC typically present with respect to venous contrast retention after a study?

1. Rapid enhancement

2. Isodense and delayed enhancement

3. Normal washout

4. Hypoattenuating

The correct answer is: Normal washout

Hepatocellular carcinoma (HCC) typically presents with a unique pattern regarding venous contrast retention during imaging investigations, particularly in computed tomography (CT) scans. In the context of imaging, “normal washout” refers to the retention of contrast material in the tumor tissue when compared to the surrounding liver tissue after the arterial phase of enhancement. In HCC, the tumors are often hypervascular due to their arterial supply, showcasing rapid enhancement during the arterial phase. However, during the venous phase, it is critical to note that HCC demonstrates a prolonged retention of contrast. This characteristic allows for differentiation between HCC and other liver lesions. Therefore, after the peak enhancement during the arterial phase, HCC tends to retain contrast in the venous phase, leading to what's classified as normal washout. On the other hand, other characteristics such as rapid enhancement or isodense and delayed enhancement do not adequately describe the typical washout patterns observed in HCC. Moreover, hypoattenuating lesions may suggest the presence of other pathologies rather than the distinctive washout pattern characteristic of HCC. Understanding these imaging features is essential for accurate diagnosis and appropriate management of hepatocellular carcinoma in clinical practice.