**2.2.2 Hemangioma**

It is the most common liver tumor with a prevalence of 0.4 - 7.4%. It is generally asymptomatic but also can be associated with pain complaints or cytopenia and/or anemia when it is very bulky. It is unique or paucilocular. It can be associated with other types of benign liver tumors. Characteristic 2D ultrasound appearance is that of a very well defined lesion, with sizes of 2-3 cm or less, showing increased echogenity and, when located in contact with the diaphragm, a "mirror image" phenomenon can be seen. When palpating the liver with the transducer the hemangioma is compressible sending reverberations backwards. Doppler exploration reveals no circulatory signal due to very slow flow speed. CEUS investigation has real diagnosis value due to the typical behavior of progressive CA enhancement of the tumor from the periphery towards the center. The enhancement is slow, during several minutes, depending on the size of hemangioma and on the presence (or absence) of internal thrombosis. During late (sinusoidal) phase, if totally "filled" with CA, hemangioma appears isoechoic to the liver. Deviations from the above described behavior can occur in arterialized hemangiomas or those containing arterio-venous shunts. In these cases differentiation from a malignant tumor is difficult and requires other imaging procedures, follow up and measurements of the tumor at short time intervals.

Fig. 3. Hepatic hemangioma (2D). The lesion is located in the left hepatic lobe. Note precise delineation, their increased echogenity and the heterogeneous internal structure.

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; b – late phase).
