Tumors and Tumor-Like Lesions of the Hepatobiliary Tract

Abstract

Angiosarcoma is a high-grade (grade 3) sarcoma that consists of a proliferation of atypical endothelial cells. Angiosarcoma develops in various organs and tissues and is the most important hepatic sarcoma, albeit it amounts to only 2 % of all primary hepatic malignancies. There is a male predominance, probably linked to risk factors related to chemical industries. The peak incidence of hepatic angiosarcoma is in the sixth to seventh decades of life, but the tumor also occurs in the pediatric age group. Seventy percent of hepatic angiosarcomas are sporadic lesions, and 30 % are associated with agents known to play a role in this neoplasm, particularly vinyl chloride monomer, pesticides, arsenicals, androgenic steroids, external ionizing radiation, and formerly thorotrast. Macroscopically, angiosarcoma presents in various growth patterns, ranging from massive tumors to diffuse micronodular lesions. Histopathology resembles that of angiosarcomas in other locations. Two main cell types prevail, i.e., highly abnormal endothelial cells lining abortive vascular spaces and interstitial spindle cells. Polymorphous elements and giant cells may occur, and part of tumor cells exhibit erythrophagocytosis. Hepatic angiosarcoma is a very aggressive, metastasizing neoplasm associated with poor outcome.