Hereditary tyrosinemia type I (chronic form): pathologic findings in the liver.

Hereditary tyrosinemia type I presents with either acute hepatic failure in the neonatal period or later in infancy with progressive liver dysfunction secondary to cirrhosis. The inevitably fatal outcome in those children with the chronic form has been transformed with the advent of liver transplantation. Native livers from five children who received allografts were studied pathologically and compared with earlier hepatic biopsies in two of these patients that had been performed several years before transplantation. Our findings support the conclusion that a sequence of morphologic changes from the initial micronodular cirrhosis through an intermediate mixed cirrhotic pattern to macronodular cirrhosis occurs. The micronodular phase is transitory, over a period of only a few months, since mixed micronodular macronodular cirrhosis was already present in the livers of children who received transplants by 11 months of age. Focal hepatocellular dysplasia was present in one of the livers with mixed cirrhosis but was not identified in the other two cases. Macronodular cirrhosis accompanied two cases of hepatocellular carcinoma in this study. In order to preclude the latter complication, liver replacement is necessary before the age of 2 years.