Assessment of a biliary hamartoma with contrast-enhanced sonography using two different contrast agents.

A 49 year old male with carcinoma of the esophagus was staged using conventional US of the abdomen. US revealed signs of cirrhosis and a hyporeflexive focal liver lesion of about 5 mm in diameter was found. Low-MI contrast-enhanced ultrasound (CEUS) with SonoVue (Bracco, Milano, Italy) showed an enhancement pattern which was typical for benign liver lesions while high-MI CEUS with Levovist (Schering, Berlin, Germany) revealed a contrast defect in the liver late phase (4:30 min p. i.) which is typical for a malignant lesion. Due to these findings the lesion was evaluated as a potentially malignant lesion and a biopsy was performed. Histology showed a benign biliary hamartoma and incomplete cirrhosis. The findings confirmed that liver-specific contrast agents have the ability to detect very small focal liver lesions not derived from hepatic tissue but may lead to a misinterpretation as a malignant lesion. Nevertheless biliary duct adenomas are benign lesions with almost the same perfusion properties as normal liver parenchyma. Therefore, while using SonoVue, such a misinterpretation of these very common but in most cases very small and not detectable lesions seems unlikely.