52 - Hemachromatosis Case Flashcards by Andrea Okas

What is hemochromatosis?

An inherited metabolic disorder that causes a systemic iron overload in the blood due to decreased hepcidin production

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What mutation causes hemochromatosis?

Usually homozygous C282Y mutation in the HFE gene on chromosome 6

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What does hepcidin normally do?

Hepcidin controls the plasma iron concentration by inhibiting iron export by ferroportin from duodenal enterocytes and reticuloendothelial macrophages
As a consequence, a decrease in hepcidin production (like in hemochromatosis), leads to an increase in plasma iron concentration

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What tests can you do if you are suspecting hemochromatosis?

Serum iron
Total iron binding capacity (TIBC)
Transferrin saturation (Serum iron/TIBC x 100)
Serum ferritin
Genetic testing

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What is the value of serum ferritin?

Very sensitive but has low specificity

Can be elevated in inflammatory process, diabetes, alcohol consumption and liver damage

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What are you looking for in genetic testing?

C282Y mutation

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What does hemochromatosis result in?

Increased serum iron results in damage of…

Pancreas
Endocrine glands
Liver
Heart
Skin
Joints

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What does the result of iron damage on the liver?

Cirrhosis

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What is the result of iron damage on the pancreas and endocrine glands?

Diabetes

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What is the result of iron damage on the heart?

Heart failure

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What is the result of iron damage on the joints?

Arthropathy

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Describe the arthropathy seen in hemachromatosis patients

2/3 of hemachromatosis patients will be affected by arthropathy
Arthopathy will be the presenting symptom in 1/3 of patients

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What three conditions can arthropathy present similarly to?

Osteoarthritis
Rheumatoid arthritis
Calcium pyrophosphate deposition disease

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When do we typically find hemochromatosis?

Younger patients
Average age is 45
We see it in men younger than 30 and in women before menopause

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What are the symptoms related to arthropathy in hemochromatosis?

Pain linked to motion and limitation of range of motion
Arthritis characteristically at 2nd and 3rd metacarpophalangeal joint
Other common joints affected include wrists, proximal interphalangeal joints, hips, knees and ankles

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How do you distinguish hemochromatosis from osteoarthritis?

Osteoarthritis is typically found in older patients unless they have had injury to the joint, so we will see it much earlier in hemochromatosis patients

How do you distinguish hemochromatosis from RA?

RA – you will get pain in all of the joints, not just two of them, so the 2nd and 3rd metacarpophalangeal joint pain is characteristic of hemochromatosis

What are typical radiographic findings in hemochromatosis?

Subchondral sclerosis common
Hook-like osteophytes found on joint periphery
Subchondral cysts and geodes
Chondrocalcinosis
Osteoporosis

What is subchondral sclerosis? What do you need to be aware of when you see subchondral sclerosis?

Subchondral sclerosis is defined as increased bone density or thickening in the subchondral layer. This often occurs with progressive osteoarthritis and shows up on x-rays as abnormally white (dense) bone along the joint line.

It can be rapidly progressive

What is chondrocalcinosis? What is important about chondrocalcinosis?

A condition characterized by accumulation of crystals of calcium pyrophosphate dihydrate in the connective tissues

It is NOT seen in osteoarthritis, so it is considered characteristic of hemachromatosis ***

Describe the hook shpaed ostophytes seen in hemachromatosis

Seen on the metacarpal heads

- Normally you would see a nice rounded edge, but here we see a little hook shaped appendage

What does chondrocalcinosis look like on an x-ray?

Increased white in the affected joint

Describe the pathological findings of hemachromatosis

Thinning or erosion of articular cartilage (will look similar to osteoarthritis and rheumatoid arthritis
Iron depositions often found in cartilage and the synovial and synovial lining cells (joint capsule)
Macrophage and neutrophil infiltration (presence correlated with hemosiderin deposits in tissue)

What is the treatment for hemachromatosis?

Phlebotomy helps with organ damage but does NOT help with arthropathy ***
This is because the ferratin is already trapped in the synovium (joint capsule)
NSAIDs
Steroid injections
Joint replacement

Describe the patient in the case study

- 63 year old female presents to clinic with right ankle pain - Onset – several years in duration - Progression - progressively getting worse - Quality – deep aching pain - Region – right ankle joint and medial right ankle - Severity – 9/10 with standing, 2/10 at rest - Treatment – none - Associated symptoms – starting to get swelling in medial right ankle Other questions - Previous injury? No - Prior surgery? No - Osteoporosis? No history of this - Other joint pain? Yes, between 2nd and 3rd metatarsals in her hand and some knee pain as well

Describe the musculoskeletal pain this patient is experiencing

M/S - Pain ankle dorsiflexion and plantarflexion - Pain with palpation of ankle joint and area of soft tissue swelling and firmness - No pain with muscle strength testing or with palpation of the tendons

Describe what we see on x-ray of this patient

- Bone quality is not great – starting to get some osteoporosis (should be more white) - You should see some black in the ankle joint, this looks like all white in the joint - Can see “little holes” in the bone where the bone has been eroded away

What do we diagnose this patient with?

Arthritic changes right ankle likely due to hemochromatosis

What is the plan?

- Steroid injection right ankle - Hopefully to decrease pain - Follow up 2 months

Describe the patient presentation 2 months later

- Pain in ankle joint greatly reduced - Still continues to have pain in the medial aspect of the ankle behind malleolus - Pain worse with weight bearing and relieved with rest - No radiation noted - Notable swelling and palpable firm mass - Area does not trans-illuminate with light - Pain noted with palpation of the mass and with ankle range of motion

What would you see in an MRI?

- T1 image, looking at the lateral view - T1=white bone - Fluid is black on T1 - See cystic changes from the hemochromatosis

What do you see on the cross section?

T1 - Dark spot on the right center behind the medial malleolus T2 - Bone is dark, fluid is bright white - Here you can see a little fluid filled mass again behind the medial malleolus

How can we interpret the MRI findings?

- Moderate tibiotalar degenerative changes especially the medial and posterior aspect. - There is small joint effusion with synovitis related to the described arthropathy. - Patient’s palpable lump likely corresponds to the small focal pouching of the joint fluid and marginal spur formation which abuts the adjacent posterior tibial neurovascular bundle.

What are the treatment options for this ongoing pain?

- Aspirate mass - Steroid injection in the tarsal canal - Surgically remove joint effusion and tie it off

Describe the option of aspirating the mass

- Aspirate mass - It would likely fill back up because it is coming off the joint - Mass is somewhat small and would be difficult to infiltrate due to location (and painful)

Describe the option of doing a steroid injection in the tarsal canal

Steroid injection in tarsal canal | - Unsure if it would work because pain is likely due to pressure on the nerve

Describe the option of surgically removing the joint effusion and tying it off

Surgically remove joint effusion and tie it off | - May come back in the future

What was the outcome for this patient?

- Patient underwent surgery to remove mass. - Pain decreased - 3 months after surgery some pain is still present but less than what it was prior to surgery - Patient placed in ankle brace