Hepatic lipomas: ultrasound and computed tomographic findings

Five cases of solitary hepatic lipoma are described. These rare tumors have ultrasound (US) and computed tomographic (CT) characteristics that suggest the diagnosis. As imaged by US, hepatic lipomas always correspond to a highly echogenic, well-limited lesion with posterior attenuation. Precontrast CT scans reveal a low-density lesion (-20 to -70 HU); following contrast material injection, the tumor density may either remain negative (pure hepatic lipoma) or become positive (limit, 40 HU) when there is an associated adenomatous component. Hepatic lipomas involve no risk of degeneration, and follow-up by US is sufficient. A case of lipoma of the falciform ligament and a case of a hepatic pseudolipoma are also described; sonograms were negative in both instances, and CT was required for diagnosis.