Early hepatic lesions with marked glandular structures induced in rats by 0.1% ethionine in a choline deficient diet

Early hepatic lesions in rats fed ethionine plus a choline deficient (ECD) diet were examined histopathologically. The purpose of this experiment was to examine preventive and suppressive effects of drugs on fatty or cirrhotic liver induced by ECD, but contrary to our expectations, all groups except the normal diet group showed neoplastic lesions in the liver. Macroscopically, milky-white nodules were seen in most all the rats except for a few dead ones. Microscopically, the characteristic lesions consisted of neoplastic nodules, glandular structures and oval cell hyperplasia. The glandular structures were already present in a rat that died on day 34 of administration and showed neoplastic developmental structures morphologically similar to cholangiofibroma. The neoplastic nodules appeared later than the glandules and were observed in rats that died after day 42. To the best of our knowledge, this is the first report of hepatic lesions consisting of mainly glandular structures induced by an ECD diet.