**2.2.4 Adenoma**

82 Liver Tumors

Fig. 3. Hepatic hemangioma (2D). The lesion is located in the left hepatic lobe. Note precise

Fig. 4. Hepatic hemangioma (CEUS). Progression of CA from the periphery toward the center of the lesion is evidenced by examination at various time intervals (a – arterial phase;

It is a tumor developed secondary to a circulatory abnormality with abundant arterial vessels having a characteristic location in the center of the tumor, within a fibrotic scar. A radial vessels network develops from this level with peripheral orientation. The tumor's circulatory bed is rich in microcirculatory and portal venous elements. The incidence is higher in younger women and tumor development is accelerated by oral contraceptives intake. 2D ultrasound appearance is a fairly well-defined mass, with variable sizes, usually single, solid consistency with inhomogeneous structure. Rarely the central scar can be distinguished. Spectral Doppler examination detects central arterial vessels and CFM exploration reveals their radial position. CEUS examination shows central tumor filling of the circulatory bed during arterial phase and completely enhancement during portal venous phase. During this phase the center of the lesion becomes hypoechoic, enhancing the tumor scar. During the late phase the tumor remains isoechoic to the liver, which strengthens the

b – late phase).

**2.2.3 Focal nodular hyperplasia** 

diagnosis of benign lesion.

delineation, their increased echogenity and the heterogeneous internal structure.

It is a benign tumor made up of normal or atypical hepatocytes. It has an incidence of 0.03%. Its development is induced by intake of anabolic hormones and oral contraceptives. The tumor is asymptomatic, but may be associated with right upper quadrant pain in case of internal bleeding. 2D ultrasound shows a well-defined, un-encapsulated, solid mass. It may have a heterogeneous structure in case of intratumoral hemorrhage. Doppler examination shows no circulatory signal. CEUS exploration is quite ambiguous and cannot always establish a differential diagnosis with hepatocellular carcinoma. Thus, during the arterial phase there is a centripetal and inhomogeneous enhancement. During the portal venous phase there is a moderate wash out. During late phase the appearance is isoechoic or hypoechoic, due to lack of Kupffer cells.
