Liver angiosarcoma and hemangiopericytoma after occupational exposure to vinyl chloride monomer

Various malignant tumors of the liver, especially liver angiosarcoma, have been described after occupational exposure to vinyl chloride monomer. We pr esent the case records and pathologic findings of two plastic industry work ers who had been exposed to high concentrations of vinyl chloride. These wo rkers developed hepatic neoplasms, angiosarcoma, or hemangiopericytoma. We discuss the histogenesis of these tumors; the common vascular origin and th e mutual transformation of these two rumors suggest that the hemangiopericy toma may also have developed during occupational exposure to high concentra tions of vinyl chloride monomer.