Infantile hemangioendothelioma is a rare benign vascular tumour arising from mesenchymal tissue and is usually located in the liver. It often presents in infancy with cardiac failure because of extensive arteriovenous shunting within the lesion. It is the third most common liver tumor in children, the most common benign vascular tumor of the liver in infancy, and the most common symptomatic liver tumor during the first 6 months of life.[1]
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Histopathologically, there are 2 types of hepatic hemangioendotheliomas:
• Type I: Hemagioendotheliomas of this type have multiple vascular channels that are formed by an immature endothelial lining with stromal separation from bile ductules.
• Type II: These hemangioendotheliomas have an appearance that is more disorganized and hypercellular, and there are no bile ductules.
Hemangioendotheliomas have 2 growth phases: an initial rapid growth phase, which is followed by a period of spontaneous involution (usually within the first 12 to 18 months of life). Detection of the hemangioendothelioma within the first 6 months of life is attributed to the initial rapid growth during this time; however, the tumor has been detected with fetal ultrasonography.[2]
In children, distinguishing between a primary malignant liver tumor (hepatoblastoma) and a benign primary hepatic lesion (hemangioendothelioma) is crucial. The absence of urinary catecholamines supports the diagnosis of hemangioendothelioma. In patients with hemangioendotheliomas, elevations in α1-fetoprotein levels are milder than those found in patients with hepatoblastomas. Infantile hepatic hemangioendothelioma is strongly suggested by the presence of a vascular lesion on imaging studies. A complex, heterogeneous mass is often seen on ultrasonograms; a complex tumor that lacks central enhancement can be see on CT scans; and the vascular nature of the lesion along with dilation of the aorta proximal to the origin of the celiac artery and a decrease in the diameter distally, indicating significant shunting, is seen on angiograms.[3]
Because most hemangioendotheliomas in infants sponanteously involute and regress within the first 12 to 18 months of life, asymptomatic lesions are generally managed conservatively. Infants who have severe anemia and/or thrombocytopenia can be given blood products; for those who have cardiac failure, diuretics and digoxin are often given. To stop further growth and to speed regression of lesions in infants with more significant clinical sequelae, treatment with corticosteroids or interferon-α-2a is administered. To slow the growth of tumors that are rapidly enlarging, chemotherapy and radiation therapy have been used. Surgical resection, partial hepatectomy, and embolization of afferent vessels should be considered for severe cases.[2]