Objective:

To explore the imaging features of hepatic epithelioid angiomyolipoma (E-AML) so as to improve the diagnostic accuracy of the disease.

Methods:

A total of 20 patients with pathologically proved hepatic E-AML were retrospectively analyzed. Among them

4 patients underwent both CT and MRI dynamic contrast-enhanced (DCE) scan. One patient underwent plain and contrast-enhanced CT scan

1 patient underwent CT angiography (CTA) examination

14 patients u

nderwent MRI DCE scan. The number

location

size

shape

density or signal intensity (SI) of plain scan of lesions

presence of fatty component

vessels within and around lesions

presence of pseudocapsule and enhancement pattern

DCE pattern of lesions and background of hepatic parenchyma were recorded and analyzed.

Results:

All 24 lesions (one lesion in 17 patients

multiple lesions in other 3 patients) were opal or round in shape. Four lesions were located in the caudate lobe

9 in the right lobe

11 in the left lobe. The size was 1.0-25.0 cm. Hypodensity was shown in 7 lesions with CT scan. Twenty-two lesions had hypointensity on T1WI

hyperintensity on T2WI

hyperintensity on diffusion weighted imaging (DWI) and decreased apparent diffusion coefficient (ADC). All 24 lesions were manifested as obvious enhancement on the arterial phase. Ten lesions showed fast in and fast out enhancement pattern and 14 showed fast in and slow out enhancement pattern. Only 7 lesions were presented fatty component. Twenty-three lesions were found punctiform or filiform vessels. Fourteen lesionsshowed pseudocapsule on arterial phase with decreased enhancement on portal venous and equilibrium phases. One lesion showed the hepatic artery as supply artery and the early hepatic venous draining into the inferior vena cava on CTA scan.

Conclusion:

The single hypervascular mass with opacification of punctiform or filiform vessels within and around lesion

early venous drainage

pseudocapsule presence on arterial phase are some characteristic features of hepatic E-AML.