Ultrasound, non-invasive and non-radioactive, is crucial for prenatal diagnosis and neonatology. Fetal liver tumors, such as hepatic hemangiomas, are rare benign tumors resulting from abnormal blood vessel growth. Giant fetal hepatic hemangiomas exceeding 40 mm are even rarer. While early pregnancy detection is challenging, these tumors are more visible in late pregnancy owing to increased blood accumulation. Typically identified between 28 and 40 weeks via ultrasound, hemangiomas vary in size and appearance. Small ones show uniform hypoechoic and hyperechoic areas, while larger ones present heterogeneous echoes, honeycomb patterns, and calcifications [3].

Hepatic hemangiomas (60%) are the most common liver tumors in newborns, followed by mesenchymal hamartomas (23%), hepatoblastomas (16%), hepatic metastases, and others (1%), identified by ultrasound [4] (Table 2).

Prenatal detection of fetal hepatic hemangioma requires regular follow-up to identify potential life-threatening issues, typically every 2–4 weeks. If shunting with high-flow or increased flow through the hepatic and portal vessels occurs, the mass rapidly increases, or if the fetus develops high-output heart failure, edema, hemolytic anemia, or severe thrombocytopenia, the assessment is adjusted to every 1–2 weeks, and an echocardiogram is especially valuable in evaluating cardiac function. If the diagnosis is difficult, a magnetic resonance imaging or computed tomography scan may be performed to confirm it. Routine blood tests, thyroid function, coagulation, alpha-fetoprotein, and echocardiography may be performed simultaneously to confirm the presence of complications such as heart failure, tumor rupture and bleeding, Kasabach–Merritt syndrome, and congenital hypothyroidism and rule out liver malignancy, the absence of fetal heart failure, and adverse outcomes such as stillbirth [5].

There is no consensus on the dynamic monitoring and treatment of hepatic hemangiomas, and management is tailored to tumor classification and the newborn’s clinical condition [5, 6]. Fetuses with hepatic hemangiomas should have an ultrasound scan immediately after birth, particularly for giant fetal hepatic hemangioma. Asymptomatic infants are generally monitored for at least 1 year, as most hemangiomas regress spontaneously by age 1 year. Symptomatic cases presenting with dyspnea, heart failure, or hypothyroidism require medical treatment, transhepatic arterial embolization, or surgical resection. Propranolol is the first choice for treating hepatic hemangiomas in infants and children. In addition, combining rapamycin with propranolol and glucocorticoids may enhance therapeutic outcomes. Relatively, their side effects are greater. In children with poor response to medical treatment, high-flow arteriovenous shunting, and rapidly deteriorating cardiac function, urgent transcatheter hepatic arteriovenous fistula embolization is highly effective. When medical treatment fails and symptoms are severe, with focal or multiple lesions, surgical resection is effective. Regardless of the treatment plan, regular follow-up evaluations should be conducted through ultrasound examination to make the most reasonable adjustments promptly.

Ultrasound is non-invasive, effective, inexpensive, and practical for diagnosing hepatic hemangiomas. Its continuous dynamic scanning and color Doppler US provide detailed insights into the blood supply of the tumor and the function of other blood vessels in the liver and heart, making it the preferred method [6]. For prenatal detection of giant liver hemangiomas, a systematic assessment of the fetal condition is crucial for determining delivery timing, postnatal examination, treatment options, and follow-up care.