LIPIODOL ACCUMULATION IN HEPATIC HEMANGIOMA - DETECTION WITH OSMIUM POSTFIXATION

Lipiodol has been used to increase the detectability of small primary neoplasms in the liver. We report a patient who was found to have lipi odol deposits in the liver one month after intra-arterial injection. T he region was resected, under ultrasound control, because of the impre ssion that the lesion was malignant. The specimen contained two small hemangiomas as well as many small dysplastic nodules (adenomatous hype rplasia) in a noncirrhotic parenchyma. To locate the lipiodol deposit in this case, the tissue was radiographed, postfixed in osmium tetroxi de, and embedded in paraffin. Black osmium-stained deposits were found within the cavities of the hemangiomas but not in the dysplastic nodu les. Most of the deposits were extracellular multivesiculated bodies w ith a small focus of lipid droplets engulfed by multinucleated foreign -body type giant cells. This report reinforces that hepatic lipiodol r etention is not specific for hepatocellular carcinoma. We present, for the first time, the histologic appearance of lipiodol accumulation in an hemangioma. The value of osmium tetroxide postfixation for the det ection of lipiodol is also demonstrated.