Primary Tumors of the Liver

Abstract

The lesions may be hyperechoic nodules and may have a bull’s-eye configuration (Figs. 9.1, 9.2, 9.5 a). Hypoechoic nodules (Fig. 9.3) or complex lesions (Fig. 9.4) are also seen. The echogenicity of hepatocarcinoma depends on their tissue architecture (richness in vessels, fat or inner septa). Abundant fat gives rise to a hyperechoic pattern resembling that of angiomas (Yoshikawa et al. 1988). Larger nodules are often less echogenic. When larger, primary tumors may also undergo necrosis (Fig. 9.2 b). Very similar lesions are observed with metastases. In fact more than half of hepatocarcinomas are multinodular. This is particularly true in cirrhotic patients, whether in alcoholic or posthepatitis cirrhosis. All of the contour and tissue texture signs described in the previous chapter are also observed with primary tumors (Figs.9.5–9.9). Majima et al. (1985) have undertaken a detailed morphologic analysis of ultrasonographic images of hepatomas. They believe that intralesional septa are frequently visualized. However, my own observations do not confirm this pattern. Changes in echotexture related to pre-existing cirrhosis can render the evaluation of the liver more difficult (Fig. 9.4; see also Chap. 10). The sonologist must try to disclose small nodules, less than 3 cm in diameter. The diagnosis of small hepatocarcinoma relies on repeated screening in cirrhotic patients. Such screening by ultrasound is now common in Japan.