Iron content of tissues in exogenous and endogenous hemochromatosis.

Hemochromatosis is a disease marked by the pathologic appearance of large amounts of iron-containing pigment, hemosiderin, in various tissue cells, and is associated with periportal cirrhosis of the liver and pancreatic fibrosis. Three types of hemochromatosis have been recognized: 1. Idiopathic or endogenous hemochromatosis, wherein the intestinal “mucosal block” preventing excessive absorption of iron from the intestine is ineffective, and allows a gradual but persistent accumulation of surplus iron (1). 2. Exogenous hemochromatosis, in which multiple blood transfusions are said to be the underlying cause of excess iron accumulation (2). 3. Dietary hemochromatosis (3), in which extrinsic dietary factors are believed to be responsible for the breakdown of the mucosal block’s regulation of iron absorption. We have had the opportunity of studying several cases of the exogenous, or transfusion, type of hemochromatosis and analyzing the tissues at postmortem for iron. The results were compared with values obtained from the endogenous type for the purpose of differentiating chemically rather than histologically the two dominant forms of the disease. The pathologic and histologic aspects have been reported earlier (4). Cases of the third type were not available to us.