Comments:
Hepatic angiosarcoma has been associated with exposure to chemical carcinogens, including:
- Thorotrast given for radiographic studies
- Arsenic in insecticides and contaminated ground water
- Vinyl chloride in rubber and plastic industries
- Androgenic anabolic steroids
THOROTRAST- a radiopaque
contrast medium containing
thorium dioxide - was widely used in
radiographic studies from
1928 to around 1955. It produced excellent images due to high degree of radioopacity. Once it is administered into the circulation, it is taken up by the cells of
reticuloendothelial system and is
stored in liver, spleen, bones, and
lymph nodes. It is
radioactive and
emits high-energy alpha particles as it decays slowly (
half-life estimated to be
about 400 years), subjecting internal organs to a
life-time of harmful radiation. The use of thorotrast was
discontinued in the 1950's after it was found to
increase the risk of
hepatic fibrosis and
several malignancies, including
hepatic angiosarcoma, hepatocellular carcinoma, cholangiocarcinoma, and
leukemias. The
latent period is
20 to 30 years. Historically, about
25% of
primary hepatic angiosarcomas were linked to
occupational or medicinal exposure to carcinogens. However, with declining use of these carcinogens due to increased awareness, most
current cases are
idiopathic or linked to anabolic steroid use. There are
no histopathological differences between
idiopathic tumors and
those induced by chemical carcinogens. Premalignant changes in the liver exposed to thorotrast and other similar carcinogens include hyperplastic hepatocytes, sinusoidal dilatation, mild atypia of lining endothelium, and fibrosis. Image copyright: pathorama.ch