Precancerous changes in the human liver.

Knowledge of the cellular changes that lead to hepatic neoplasia in humans is limited. Cirrhosis is a common antecedent or accompaniment of liver cell carcinoma and it seems that both its etiology and its time of duration are relevant risk factors. Many cellular changes have been observed in patients and among populations considered to be at risk. Of these, liver cell dysplasia is the most striking, and studies of its prevalence, natural history, and association with particular forms of cirrhosis suggest that it is a precancerous change. Bile duct carcinoma may follow infestation with liver flukes and duct epithelial hyperplasia is present before the development of cancer. Angiosarcoma from several causes is commonly preceded by a peculiar fibrosis, vascular changes, and Kupffer cell hyperplasia.