The diagnosis of hemochromatosis using liver tissue specimens

Two mg of liver tissue is required.

• This is typically a piece of tissue from a 22-gauge needle biopsy at least 2 cm long
• If an 18-gauge needle is used, the tissue must be at least 1 cm in length

Mayo Metal Free Specimen Vial (T173)

Any specimen container other than a Mayo metal-free vial used should be plastic, leached with 10% nitric acid for 2 days, rinsed with redistilled water, and dried in clean air.

Paraffin block if not more than 1-2 cuts have been made to it for slides.

• Paraffin blocks will be returned 3 days after analysis

Refrigerated (preferred)

Frozen (OK)

Ambient (OK)

• All specimens will be evaluated at Mayo Clinic Laboratories for test suitability

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Iron

Male: 200 - 2,400 µg/g dry weight
Female: 200 - 1,800 µg/g dry weight

Iron index

<13 years: Not established

≥13 years: < 1.0 µmol/g/year

A hepatic iron concentration above 10,000 mcg/g dry weight is diagnostic for hemochromatosis.

Hepatic iron concentrations above 3000 mcg/g are seen when there is iron overload without cellular injury and cirrhosis. Hepatic iron concentrations greater than the reference range are associated with hemosiderosis, thalassemia, and sideroblastic anemia. Some patients with hepatitis or cirrhosis without significant fibrosis will have hepatic iron concentrations at the top end of normal or just slightly above the normal range.