Focal liver lesion: nonlinear contrast-enhanced ultrasound imaging

Enhancement Patterns of Malignant Focal Lesions

Rare Malignant Neoplasm:

Angiosarcoma is the most frequent malignant mesenchymal liver malignancy, but proves to be a very rare tumor prevalently diagnosed in 60 to 80 year old male patients who were exposed to Thorotast vinyl chloride or other toxic agents (Bartolozzi et al., 2001, Ros et al., 2001). Other less common sarcomas such as leiomyoma, fibrous, histiocytoma can be found. Sarcomas usually appear as large size uncapsulated lesions at imaging detection, but very small multifocal nodules may also be seen (Ros et al., 2001). On conventional US mixed echogenicity prevails due to hemorrhagic or necrotic areas. Color Doppler might capture minimal intralesional flow signals. Contrast-enhanced ultrasound presents hypo-enhancement in all the vascular phases.
Lymphoma as a primary hepatic involvement is very rare; however, it is possible to find liver involvement during the outcome of Hodgkin’s or non Hodgkin’s systemic lymphoma. Immune deficiency patients are mainly concerned. On conventional US hypo-echoic nodules or masses may be found. The diffuse hepatic involvement appears as a diffused alteration of the normal liver echo-texture. Lymphomatous nodules present on CEUS iso- or hyper-enhancement in the arterial phase but hypo- or lack of enhancement in the following phases (Catalano et al., 2005).