Hepatic adenomas and focal nodular hyperplasia: dynamic CT study

Area of Science:

• Radiology
• Hepatology
• Medical Imaging

Background:

• Benign hepatic tumors, including hepatic adenomas (HAs) and focal nodular hyperplasia (FNH), require accurate diagnosis.
• Distinguishing between HA and FNH can be challenging using non-invasive imaging techniques.

Purpose of the Study:

• To evaluate the effectiveness of ultrasonography (US) and dynamic computed tomography (CT) in differentiating between hepatic adenomas and focal nodular hyperplasia.
• To identify imaging features suggestive of FNH on CT scans.

Main Methods:

• A retrospective analysis of 50 patients with histologically confirmed benign liver tumors (27 HAs, 23 FNHs).
• Imaging modalities included US, dynamic CT, and angiography in a subset of cases.
• Scintigraphy was not utilized due to cost considerations.

Main Results:

• US scans were found to be nonspecific for differentiating between HA and FNH.
• CT scans revealed hemorrhage in five HAs and were useful for characterizing tumoral vascularity and intratumoral features.
• The presence of arterial vessels within a central fibrous scar on CT was suggestive of FNH.
• Dynamic CT alone was often insufficient for definitive tumor typing.

Conclusions:

• Dynamic CT is valuable for characterizing benign liver tumors, especially when identifying intratumoral features and vascularity.
• Combined imaging modalities (morphologic data, CT, angiography, and potentially scintigraphy) are recommended for complex cases or lesions larger than 3 cm.
• Therapeutic decisions for ambiguous lesions should consider imaging findings, patient history, and potential hormonal influences (e.g., oral contraceptive use).