Xanthoma tendinous nodules - Causes, Treatment & When to See a Doctor

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What is Xanthoma Tendinous Nodules?

Xanthoma tendinous nodules (often shortened to “tendon xanthomas”) are firm, yellow‑orange deposits of cholesterol‑rich material that develop within the tendons, most commonly the Achilles tendon, extensor tendons of the hands, and the patellar tendon. They feel like hard, painless bumps under the skin and can range from a few millimetres to several centimetres in size. While the nodules themselves are usually benign, they are a skin‑visible clue that underlying lipid metabolism is abnormal—most frequently a severe form of hyperlipidaemia such as familial hypercholesterolaemia (FH). Early recognition can therefore prompt life‑saving interventions to lower cardiovascular risk.<sup>1</sup>

Common Causes

Although tendon xanthomas are most strongly linked to inherited disorders of lipid metabolism, several other conditions can produce similar deposits.

• Familial hypercholesterolaemia (FH) – autosomal‑dominant mutation in the LDL‑R, APOB, or PCSK9 genes; the most common cause.
• Familial combined hyperlipidaemia – elevated LDL‑C and triglycerides.
• Familial dysbetalipoproteinaemia (type III hyperlipidaemia) – defective ApoE leads to remnant‑rich particles.
• Primary biliary cholangitis (PBC) – chronic cholestasis can raise cholesterol.
• Nephrotic syndrome – massive protein loss triggers hepatic lipoprotein overproduction.
• Hypothyroidism – reduced LDL‑receptor activity raises serum LDL.
• Medication‑induced lipid disorders – e.g., cyclosporine, tacrolimus, retinoids.
• Chronic liver disease (cirrhosis) – impaired clearance of lipoproteins.
• Systemic inflammatory disorders – such as systemic lupus erythematosus (SLE) that alter lipid handling.
• Rare lipid storage diseases – e.g., sitosterolaemia or cerebrotendinous xanthomatosis.

Associated Symptoms

Because tendon xanthomas are a manifestation of systemic lipid abnormalities, patients often present with additional signs:

• Other cutaneous xanthomas (e.g., eruptive, tuberous, or planar types).
• Premature atherosclerotic disease – angina, claudication, or history of myocardial infarction before age 55 (men) or 65 (women).
• Family history of high cholesterol, early heart attacks, or known FH.
• Lipid‑related laboratory findings: markedly elevated LDL‑C (>190 mg/dL in adults), possibly elevated total cholesterol >300 mg/dL.
• In secondary causes: edema from nephrotic syndrome, fatigue from hypothyroidism, jaundice from cholestasis.

When to See a Doctor

Prompt medical evaluation is advised if you notice any of the following:

• Firm, yellowish nodules on the Achilles tendon, hands, elbows, or knees.
• A family member with known high cholesterol or early heart disease.
• Unexplained leg or calf pain that worsens with activity (possible tendon involvement).
• Skin lesions that change colour or size rapidly.
• Symptoms of cardiovascular disease (chest pain, shortness of breath, abnormal heart rhythms).

Early consultation allows for lipid‑panel testing, genetic counseling, and initiation of therapy that can halt progression of both the nodules and cardiovascular disease.

Diagnosis

Diagnosing tendon xanthomas involves a combination of clinical assessment, imaging, and laboratory work‑up.

1. Clinical Examination

• Visual inspection – yellow‑orange colour, often symmetric.
• Palpation – firm, non‑fluctuant, adherent to the tendon without overlying inflammation.
• Documentation of size, number, and location.

2. Laboratory Studies

• Lipid profile: total cholesterol, LDL‑C, HDL‑C, triglycerides.
• Thyroid‑function tests (TSH, free T4) to rule out hypothyroidism.
• Renal function (proteinuria, serum albumin) if nephrotic syndrome is suspected.
• Liver enzymes & bilirubin for cholestatic disease.
• Genetic testing for FH (LDLR, APOB, PCSK9) when family history or very high LDL‑C is present.

3. Imaging

• Ultrasound: high‑resolution, non‑invasive; shows hyperechoic thickening within the tendon.
• Magnetic Resonance Imaging (MRI): provides detailed tissue contrast, useful if surgical planning is considered.
• CT scan: can quantify calcium in tendons but is less commonly used.

4. Histopathology (rare)

Biopsy is seldom needed but, when performed, reveals lipid‑laden foam cells, cholesterol clefts, and fibrosis within the tendon matrix.

Treatment Options

Management focuses on two goals: reducing the underlying lipid abnormality and addressing the nodules themselves.

1. Lipid‑Lowering Therapy

• Statins (e.g., atorvastatin, rosuvastatin): first‑line; lower LDL‑C by 30‑55%.
• PCSK9 inhibitors (evolocumab, alirocumab): add‑on for patients with FH who do not reach targets with statins alone.
• Ezetimibe: blocks intestinal cholesterol absorption; useful as a second agent.
• Bile‑acid sequestrants (cholestyramine, colesevelam): modest LDL‑C reduction.
• Lomitapide & mipomersen: approved for homozygous FH; monitored for liver toxicity.

Target LDL‑C for most high‑risk patients: < 70 mg/dL; for FH, < 55 mg/dL is often recommended (ACC/AHA 2018 guidelines).<sup>2</sup>

2. Management of Secondary Causes

• Hypothyroidism – levothyroxine replacement.
• Nephrotic syndrome – treat underlying glomerular disease, use ACE inhibitors/ARBs to reduce proteinuria.
• Primary biliary cholangitis – ursodeoxycholic acid; consider fibrates for associated hyperlipidaemia.
• Medication review – substitute offending agents when possible.

3. Surgical & Cosmetic Options

• Excisional surgery: removal of large, painful nodules; risk of tendon weakening.
• Laser therapy or cryotherapy: experimental, mainly for cosmetic improvement.
• Physical therapy may help maintain tendon strength after removal.

4. Lifestyle & Home Measures

• Adopt a heart‑healthy diet – low saturated fat, high fiber, plenty of fruits/vegetables; consider the Mediterranean pattern.
• Regular aerobic exercise (≥150 min/week) to improve HDL‑C and overall cardiovascular health.
• Weight management – obesity worsens lipid profile.
• Avoid smoking and limit alcohol intake.

Prevention Tips

While genetic forms like FH cannot be prevented, early detection and proactive management can stop tendon xanthomas from developing or worsening.

• Family screening: test first‑degree relatives of anyone diagnosed with FH or tendon xanthomas.
• Routine lipid checks: at least every 5 years for adults, earlier if risk factors exist.
• Adhere to prescribed lipid‑lowering medication: never stop statins without consulting a clinician.
• Maintain a balanced diet and active lifestyle from childhood.
• Control secondary contributors – keep thyroid function normal, manage kidney disease, and treat liver disorders promptly.

Emergency Warning Signs

Key Take‑aways

• Tendon xanthomas are a visible sign of serious lipid abnormalities, most commonly familial hypercholesterolaemia.
• Early recognition, lipid testing, and aggressive LDL‑C lowering can prevent cardiovascular events and may reduce nodule size.
• Regular follow‑up with a lipid specialist or cardiologist is essential for lifelong management.

For further reading, see the American Heart Association guidelines on familial hypercholesterolaemia, the Mayo Clinic’s overview of xanthomas, and recent reviews in The Journal of Clinical Lipidology.<sup>3,4</sup>

``` **References** 1. Mayo Clinic. *Xanthomas*. https://www.mayoclinic.org/diseases-conditions/xanthomas/symptoms-causes/syc-20374433 (accessed June 2026). 2. American College of Cardiology/American Heart Association. *2018 Guideline on the Management of Blood Cholesterol*. Circulation. 2019;139:e1082‑e1143. 3. Nordestgaard BG, et al. *Familial hypercholesterolaemia is underdiagnosed and undertreated in the general population*. Eur Heart J. 2020;41:1300‑1308. 4. Raal FJ, et al. *PCSK9 inhibition in patients with homozygous familial hypercholesterolaemia*. N Engl J Med. 2022;386:1002‑1014.