Immature tubular liver with focal nodular trabecular hyperplasia

An unusual disorder of liver development, which is to our knowledge not described in the literature, was observed in a female infant who died, at the age of 25 weeks, of the sequelae of portal hypertension. At the time of autopsy, the enlarged liver revealed multiple small nodules histologically composed of trabecular hepatic tissue, whereas the remaining liver parenchyma consisted of hepatocytes arranged as tubular structures. Based on comparisons of these morphologic features with the different steps of normal hepatogenesis, we suggest that the disorder is the result of a partial arrest of liver differentiation with focal progression of maturation in the hyperplastic nodules. This assumption is supported by the observation of hepatocytes reacting with anti-alpha-fetoprotein antibodies in the tubular part of the liver, this being absent in the trabecular nodules.