18 - Liver biopsy in hemochromatosis

Summary

Introduction

Biopsy of the liver is considered by many authorities to be essential when the diagnosis of hemochromatosis is suspected due to clinical or biochemical abnormalities. Others have questioned the need for hepatic biopsy in the evaluation of persons with hemochromatosis. The essential feature of patients with hemochromatosis is increased body iron stores with excessive parenchymal deposition of iron, most easily demonstrated in the liver. The degree of iron overload is influenced by age, sex, previous blood donations or blood loss, alcohol use, oral iron intake, and other factors.

Selection of patients for hepatic biopsy

Clinical features

Selecting patients to undergo hepatic biopsy is often the most difficult decision in the management of persons suspected of having hemochromatosis (see algorithm: Table 18.1). This diagnosis should be considered in any patient with unexplained hepatic disease, hepatomegaly, hypogonadism, arthropathy, diabetes mellitus, hyperpigmentation, or cardiomyopathy. Distinguishing hemochromatosis on clinical grounds from hematologic disorders characterized by chronic anemia secondary to ineffective erythropoiesis and iron overload due to increased absorption of iron, and increased iron intake due to medicinal iron or repeated red blood cell transfusions is usually simple.

Laboratory investigation

The serum concentrations of liver-related enzymes (e.g., aminotransferases and alkaline phosphatase) are usually normal or mildly increased in hemochromatosis. Unexplained increases in their serum concentrations should prompt further investigation for iron overload. The transferrin saturation and serum ferritin concentration are useful indicators of hemochromatosis and body iron stores, but the serum iron concentration per se is not.