11. Haemochromatosis

Haemochromatosis preparation

Organ: Liver, small intestine, kidney

Description: We can see a slice of liver in the front, a piece of small intestine behind it, and a kidney in the bottom. The organs are blue or bluish. The liver is especially blue.

Diagnosis: Haemochromatosis

Causes:

• For primary haemochromatosis:
  • HFE-gene missense mutation
• For secondary haemochromatosis:
  • Haemolysis (autoimmune hemolytic anaemia)
  • Repeated blood transfusions
  • Massively increased iron reabsorption
  • Decreased iron utilization

Theory:

In hemosiderosis the hemosiderin pigment is accumulating in cells but there is no tissue damage. In haemochromatosis however, the pigment is accumulating and there is tissue damage. These preparations are not stored in formalin but in Prussian blue, a stain that stains iron blue. The liver, being a metabolic organ, is logically the bluest. However, since hemochromatosis is a systemic process, all organs are filled with iron to some extent, which is why the kidney and small intestine are also stained blue.

We distinguish primary and secondary haemochromatosis. The primary (or hereditary) type is the most severe and is caused by a missense mutation in the HFE-gene. The HFE protein usually stops the absorption of iron when the transferrin receptor is saturated. However, in this type of mutation the HFE gene won’t stop the absorption of iron in this case, which causes iron overload in the body. Secondary haemochromatosis can be caused by multiple factors, none of which have anything to do with the HFE gene. The causes are listed above.

Both types of haemochromatosis have the same clinical consequences. The disease is also called “bronze diabetes” because of its symptoms.

• Diabetes
• Skin discoloration
• Endocrine organ dysfunction (hypophysis, adrenal gland)
• Liver cirrhosis

Diabetes occurs because of the damage of the pancreatic islets due to the hemosiderin and the skin is discoloured because of hemosiderin in the skin.