This image demonstrates hepatic hemangioma incidentally found while imaging the kidney. On ultrasound, hepatic hemangiomas appear as well-defined, hyperechoic, homogeneous lesions. Some of them may have posterior acoustic enhancement. The hyperechogenicity probably results from multiple fibrous interfaces between vascular spaces. If the lesion is in a fibrotic liver, that is background echogenicity, it may appear hypoechoic. Lesions >5 cm can have mixed echogenicity because of intratumoral thrombosis and fibrosis.
Ultrasound has a good accuracy in differentiating hepatic hemangioma from malignant hyperechoic masses (sensitivity of 94.1% and specificity of 80.0% for lesions less than 3 cm diameter). The absence of blood flow on Doppler exam is also a reliable sign to differentiate hemangioma from hepatocellular carcinoma, which frequently has intra- or peri-tumoral vascularity. Though the lesion is vascular, the blood flow is too slow to be picked up by Doppler usually. In hypoechoic lesions, a peripheral echogenic rim favors hemangioma, while a perilesional hypoechoic rim, known as the ‘target sign’, strongly suggests malignancy.
Asymptomatic patients with lesions <1.5 cm, but also including those with lesions ≤5 cm, can be reassured and observed without follow-up imaging. On the other hand, close radiologic follow-up of should be considered in patients with lesions >5 cm (e.g. CT scan yearly), particularly those in a subcapsular location. In the absence of symptoms, prophylactic resection is usually not recommended [UpToDate].