A 50-year-old man presents for a routine physical examination, which demonstrates an enlarged liver. During the visit, he describes memos from his supervisor at work regarding chronic exposure to vinyl chloride. The patient has an elevated risk for which of the following tumors?

Occupational exposure to vinyl chloride (used in the production of plastics) is associated with the development of this malignant tumor of endothelial cells in the liver. Angiosarcoma is also associated with exposure to arsenic (a component of pesticides) and Thorotrast (a radioactive contrast medium used by radiologists prior to 1950). None of the other tumors have been associated with occupational exposure to vinyl chloride. Hepatic adenoma (choice C) is associated with the use of oral contraceptives.Diagnosis: Angiosarcoma of the liver