B-mode and contrast enhanced ultrasound guided biopsy of portal vein thrombosis. Value in the diagnosis of occult hepatocellular carcinoma in liver cirrhosis.

AIM

The ultrasonographic (US) detection of hepatocellular carcinoma (HCC) in patients with liver cirrhosis is based on the visualization of focal lesions. However, in some cases HCC cannot be clearly identified at US, the only sign being a portal vein thrombosis (PVT). Contrast enhanced ultrasound (CEUS) is an excellent method to characterise focal lesions and portal thrombosis in patients with liver cirrhosis. The aim of the study was to assess the value of US and CEUS -guided PVT core biopsy in the diagnosis of an occult HCC in patients with cirrhosis.

MATERIAL AND METHODS

Twenty patients with cirrhosis, PVT and no focal lesion on high-resolution US were studied. In 17 cases the thrombus was interpreted as malignant at US. All patients had normal coagulation parameters. The biopsies of an intrahepatic PVT were performed using an 18G Bard needle coupled on "Biopty Gun".US and CEUS guidance was used in16 respectively 4 patients. In 10 cases with a very inhomogeneous hepatic echostructure near the PVT (coarse echo pattern) a liver biopsy from that area was performed.

RESULTS

Adequate histological specimens were obtained in all cases, requiring 1 to 2 passes (mean 1.5 per patient). Only 1 patient had severe pain. No major complications were detected. The overall sensitivity of core biopsy in the diagnosis of malignant PVT was 94.4 % (17/18). The sensitivities of US and CEUS guided PVT biopsy were 92.8% (13/14) and 100% (4/4) respectively. In 6 of 10 cases with coarse echo pattern the same type of HCC was found in the surrounding parenchyma. No false positive results were noted.

CONCLUSIONS

US-guided core biopsy of PVT is a safe and useful technique in the diagnosis of occult HCC in cirrhosis and should be performed in all cases with PVT with malignant US features and no evidence of focal lesions. The "coarse echo pattern" found in the vicinity of a malignant thrombus is frequently the expression of an inapparent, occult HCC. CEUS guided PVT biopsy is a new, promising method with excellent results in establishing the nature of a portal thrombus.