Selective and persistent deposition and gradual drainage of iodized oil, Lipiodol in the hepatocellular carcinoma after injection into the feeding hepatic artery.

The selective and long-term deposition of iodized oil in the hepatocellular carcinoma (HCC) and its gradual drainage were clinicopathologically analyzed in 13 cases. All patients were Japanese and had an intrahepatic arterial injection of Lipiodol (LIP) mixed with Mitomycin C. The comparison among the follow-up computerized tomography (CT) findings, the observation of the soft x-ray radiogram, and histopathologic studies of the surgical or autopsy materials revealed that the selective deposition of LIP in HCC lasted for a long term, particularly in cases treated by LIP combined with transcatheter arterial embolization (TAE). Also revealed was an extremely gradual decrease of LIP from the HCC. It was thus postulated that, mainly, the accumulated macrophages surrounding LIP around the necrotic cancer tissue and, partially, the intrahepatic lymphatic system itself contributed to this drainage. Further, in histologic sections with lipid staining, x-ray microanalysis proved that the lipid droplets in the cancer tissue included highly concentrated iodine, as a deposition of LIP.