Hepatocellular carcinoma in otherwise sonographically normal liver.

PURPOSE: Hepatocellular carcinoma (HCC) on normal liver is very rare. The goal of this study was to determine the clinical manifestations and the role of ultrasonography (US) in the diagnosis of HCC arising in normal liver.

METHODS: The clinical data and US findings in 12 cases of surgically resected HCC in normal liver were retrospectively analyzed.

RESULTS: The patients were asymptomatic, had no hepatocarcinogenic factor, and hepatic function tests were almost normal in most cases. HCCs were large, encapsulated, and solitary, and there were predominantly well-differentiated or moderately differentiated in most cases. US showed a hypoechoic rim and lateral shadowing, suggestive of peritumoral capsule formation, and on contrast-enhanced US (CEUS), the tumor was hyperenhanced in arterial phase and washed out in postvascular phase, revealing typical HCC findings.

CONCLUSIONS: US raises suspicion of HCC by showing lateral shadowing on grayscale ultrasound and hypervascularity on CEUS of the lesion.