Liver biopsy diagnosis of homozygous hemochromatosis: a diagnostic algorithm.

The diagnosis of homozygous hemochromatosis (HH) should be based on appropriate findings on liver biopsy specimens. In cases with equivocal morphologic features, quantitative tissue iron determination and calculation of the hepatic iron index generally enable one to distinguish HH from other types of hepatic iron overload. In this article, we describe a diagnostic algorithm that is designed to avoid diagnostic errors because of histologic misinterpretation or erroneous, usually false-negative, chemical iron studies. The algorithm also delineates a cost-effective method of using quantitative tissue iron analysis. Diagnostic biopsy features of uncomplicated HH include (1) hemosiderosis that involves primarily hepatocytes, with or without inactive cirrhosis, and (2) a tissue iron index of 1.9 or higher. Findings such as prominent fatty changes or lymphocytic piecemeal necrosis indicate the presence of HH in conjunction with another complicating condition or secondary iron overload in the absence of HH.