A 45-year-old man with hepatocellular carcinoma who developed intravascular coagulation following complete tumor regression by chemotherapy is described. After 2 doses of 10 mg of Mitomycin C given into the hepatic artery at the time of selective angiography, and 16 intravenous doses of 5-fluorouracil and Mitomycin C, 2 doses per week, subjective symptoms and hepatomegaly disappeared. Alpha-fetoprotein became negative and a remarkable change in tumor size and vasculature was noted in the arteriogram. Three months after chemotherapy, the patient developed thrombocytopenia, intravascular hemolysis, and acute renal failure. Autopsy disclosed a 8 X 7 X 5 cm solitary, encapsulated hepatocellular carcinoma in the right lobe. The tumor was surrounded by a thick capsule and completely necrotized. Neither intrahepatic invasion nor extrahepatic metastasis was observed. In the kidney, generalized fibrin thrombi were seen in the afferent arterioles of glomeruli as accounted for by intravascular coagulation.Cancer 42:67-73, 1978.E PROGNOSIS OF HEPATOCELLULAR car-T cinoma (HCC) is extremely poor and most patients die within several months from the time of d i a g n~s i s .~~'~~'~~~~~~~ Despite the various therapeutic measures employed such as hepatic lobectomy,20 ligation of the hepatic artery,'*12 anticancer chemotherapy24,31,35 and r a d i a t i~n ,~,~~ at the present time only resection of localized tumor found by early diagnosis affords complete cure or long survival.'O In the following patient, complete necrosis of a large HCC was obtained by anticancer chemotherapy, but it was followed by intravascular coagulation and renal failure. This