Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Apr 15, 2021; 13(4): 223-230
Published online Apr 15, 2021. doi: 10.4251/wjgo.v13.i4.223
Primary malignant vascular tumors of the liver in children: Angiosarcoma and epithelioid hemangioendothelioma
Sami Bannoura, Juan Putra
Sami Bannoura, Juan Putra, Department of Paediatric Laboratory Medicine, Hospital for Sick Children, 555 University Ave, Toronto M5G 1X8, Ontario, Canada
Author contributions: Bannoura S reviewed the literature and drafted the manuscript; Putra J reviewed the literature, acquired the histological images, and edited the final version of the manuscript; both authors approved the final version to be published.
Conflict-of-interest statement: The authors have nothing to disclose.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Juan Putra, MD, Assistant Professor, Staff Physician, Department of Paediatric Laboratory Medicine, Hospital for Sick Children, 555 University Ave, Toronto M5G 1X8, Ontario, Canada.
Received: January 4, 2021
Peer-review started: January 4, 2021
First decision: January 25, 2021
Revised: January 26, 2021
Accepted: March 22, 2021
Article in press: March 22, 2021
Published online: April 15, 2021

Primary malignant vascular neoplasms of the liver, angiosarcoma and epithelioid hemangioendothelioma, are extremely rare entities in the pediatric population. International Society for the Study of Vascular Anomalies classification system is recommended for the pathologic diagnosis of hepatic vascular lesions in this age group. In this article, we highlight the clinicopathologic characteristics of hepatic angiosarcoma and epithelioid hemangioendothelioma in the pediatric population. Hepatic angiosarcoma in children shows a slight female predominance with an average age of 40 mo at diagnosis. The distinct histologic features include whorls of atypical spindled cells and eosinophilic globules, in addition to the general findings of angiosarcoma. Histologic diagnosis of pediatric hepatic angiosarcoma is not always straightforward, and the diagnostic challenges are discussed in the article. Hepatic epithelioid hemangioendothelioma also demonstrates a female predominance, but is more commonly identified in adolescents (median age at diagnosis: 12 years). Histologically, the lesion is characterized by epithelioid cells and occasional intracytoplasmic lumina with a background of fibromyxoid stroma. While WWTR1-CAMTA1 and YAP1-TFE3 fusions have been associated with epithelioid hemangioendothelioma, there are currently no known signature genetic alterations seen in pediatric hepatic angiosarcoma. Advancement in molecular pathology, particularly for pediatric hepatic angiosarcoma, is necessary for a better understanding of the disease biology, diagnosis, and development of targeted therapies.

Keywords: Pediatric, Hepatic angiosarcoma, Epithelioid hemangioendothelioma, Infantile hemangioma, Liver tumor, Molecular genetics

Core Tip: Malignant hepatic vascular neoplasms are rarely encountered in the pediatric population. This review highlights the clinicopathologic characteristics of pediatric hepatic angiosarcoma and epithelioid hemangioendothelioma. They have variable clinical and radiological findings; therefore, histologic examination is the gold standard for diagnosis. Hepatic angiosarcoma in children is characterized by whorls of spindled cells and eosinophilic globules histologically. Meanwhile, epithelioid hemangioendothelioma shows epithelioid cells with intracytoplasmic lumina and a fibromyxoid background. Diagnostic challenges and molecular alterations of these entities are discussed in the article.