Role of liver biopsy in disorders of iron metabolism

Recent advances in understanding the genetic and molecular basis of inherited disorders of iron metabolism have resulted in a new approach to the classification of hereditary iron-storage disorders; these include various forms of hereditary haemochromatosis as well as a number of other much less common genetic iron-overload disorders. As a consequence, the role of liver biopsy in assessing hepatic iron-overload disorders has changed. This review will begin by providing an overview of the molecular mechanisms involved in regulating iron homeostasis and the current approach to classifying genetic iron-overload diseases based on the identification of specific gene mutations. The pathogenesis and functional consequences of hepatic siderosis in acquired iron-overload conditions will also be considered. The histopathological assessment of hepatic iron storage will be reviewed, focusing on histological patterns of iron overload and the changing role of liver biopsy in the diagnosis and management of patients with primary and secondary hepatic iron overload.