DIAGNOSIS AND FOLLOW-UP OF SMALL HEPATOCELLULAR-CARCINOMA WITH SELECTIVE INTRAARTERIAL DIGITAL SUBTRACTION ANGIOGRAPHY

To clarify the angiographic features of small hepatocellular carcinoma , we performed digital subtraction angiography in 91 patients with hep atocellular carcinomas of 2 cm or less. Repeated digital subtraction a ngiography studies were performed in 25 patients whose first angiogram s showed no tumor staining. Digital subtraction angiography showed hyp ervascular tumor staining in only 51 patients (56.0%). We found that t he smaller a tumor nodule was, the lower the detection rate of tumor s tain on digital subtraction angiography. The detection rate of hyperva scularity was closely correlated with the grading of histological diff erentiation of the tumors: well-differentiated hepatocellular carcinom as more often showed negative tumor staining. Repeated digital subtrac tion angiography studies showed alteration of tumor staining from isov ascular to hypervascular in 6 of 6 patients with tumors that became la rger than 2 cm and in 12 of 19 patients with tumors that remained 2 cm or smaller. Conversion of vascularity is commonly found in the early stage of small hepatocellular carcinoma, and the process is usually sl ow, taking approximately 1 yr.