Hepatic Hemangioma: Pitfalls & Mimics, Part I

What this episode covers

In this video lecture, we discuss tips and tricks to diagnose everybody’s favorite hepatic tumor on CT, MRI and ultrasound. Key points include: * Hemangioma is the most common benign hepatic tumor, and it is more common in females. * These tumors are usually asymptomatic and typically require no treatment, but can rarely cause pain, rupture if large, or cause Kasabach-Merritt syndrome. * On nonenhanced CT, hemangiomas will be hypodense to liver parenchyma and homogeneously isodense to the blood pool. * There are three major enhancement patterns for typical hemangiomas, and all patterns will show persistent delayed enhancement without contrast washout. * Peripheral, nodular, interrupted enhancement with gradual centripetal progression to uniform enhancement is the most common pattern. * Smaller lesions (less than 1-2 cm) can have immediate uniform enhancement and appear flash-filling. * Larger hemangiomas may have a central scar that does not enhance. * MRI is highly specific in the diagnosis of hemangioma. * On MRI, hemangiomas will appear T1 hypointense and T2 hyperintense to liver parenchyma, or (perhaps more importantly) T1 isointense to the blood pool and T2 hyperintense to the spleen. * Hemangiomas usually do not show restricted diffusion. * If present, the central scar of hemangioma will appear T1 hypointense and T2 hyperintense on MRI. * Additional liver masses that may have a central scar include focal nodular hyperplasia, fibrolamellar hepatocellular carcinoma, cholangiocarcinoma, and hepatocellular carcinoma. * On ultrasound, hemangiomas are usually uniformly echogenic. * 40% of hemangiomas can have a “reverse target” appearance with an echogenic periphery and hypoechoic center. * Hemangiomas usually have no color Doppler flow on ultrasound, but they may occasionally exhibit mild flow.

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