Thyroid Incidentaloma

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What is a thyroid incidentaloma?

A thyroid incidentaloma is an unexpected finding of a thyroid nodule or growth during a medical imaging test or examination initially conducted for a different purpose. Incidentalomas are essentially thyroid nodules or masses discovered incidentally while imaging for unrelated issues, such as during ultrasounds, X-rays, or computed tomography (CT) scans of the neck or chest.

These incidental findings often do not produce any noticeable symptoms or health issues. They vary in size (ranging from 10-15mm) and are typically noncancerous. However, further evaluation is often required to determine their nature and potential impact on your thyroid health.

Thyroid incidentalomas can lead to diagnostic and management challenges. If a nodule is identified, your endocrinologist may recommend additional tests, such as ultrasound or fine needle aspiration, to assess whether the nodule is benign (non-cancerous) or malignant (cancerous). 

What causes a thyroid incidentaloma?

Regardless of the type of thyroid growth discovered, the main cause of a thyroid incidentaloma is usually related to an overgrowth of thyroid gland cells. This overgrowth can result in various thyroid growths, such as:

  • Thyroid tumours: thyroid tumours can be malignant (cancerous) or benign (non-cancerous). 
  • Thyroid cysts: fluid-filled or part-solid, part-fluid-filled cysts that are typically non-cancerous.
  • Thyroid nodules: one or more thyroid growths, also known as nodular goitres, that occur on the thyroid gland.  

It is important to note that many thyroid incidentalomas are benign and do not pose a significant health risk. However, in some cases, they may be indicative of thyroid cancer, necessitating further evaluation to determine their nature and potential impact. The exact cause of thyroid nodules can be multifactorial and may involve several risk factors such as genetics, iodine intake, or other environmental influences.

What are the symptoms of thyroid incidentaloma?

While most thyroid incidentalomas do not present with specific symptoms, thyroid growths that get too large or affect the production of thyroid hormones can result in the following symptoms:  

  • Fatigue, weight changes, or changes in heart rate related to conditions such as hyperthyroidism or hypothyroidism.
  • Large thyroid nodules may be felt as a lump in the neck during a physical examination.
  • Enlarged thyroid glands, also known as nodule goitre, may occur in individuals if the growth gets too large.
  • Large nodule growths can result in hoarseness or voice changes, difficulty breathing or swallowing, and neck pain.

For most individuals, their thyroid incidentaloma is characterised by a lack of symptoms. This tends to be a distinguishing feature of most thyroid incidentalomas; they are usually nonfunctional and benign.

If you suspect you have symptoms of a thyroid incidentaloma or are concerned about your thyroid health, consult an endocrinologist for a proper evaluation and diagnosis.

large thyroid incidentaloma
Large thyroid nodules can cause symptoms such as difficulty breathing or swallowing.

Are thyroid incidentalomas painful?

Thyroid incidentalomas typically do not cause pain. Since they rarely present noticeable symptoms, there is usually no associated pain or discomfort.

It is important to note that while thyroid incidentalomas are usually painless, they should be evaluated to determine their nature, size, and potential impact on thyroid function. In some cases, further diagnostic tests or monitoring may be necessary to ensure they are non-cancerous and not affecting thyroid health. Regular medical assessments are essential for proper management and peace of mind.

Who is at risk of thyroid incidentaloma in Singapore?

Risk factors associated with thyroid incidentalomas include:

How is thyroid incidentaloma diagnosed?

When you undergo a CT scan, MRI, or neck ultrasound for different medical concerns, these images may incidentally reveal thyroid nodules or growths. Once the incidentaloma is discovered, your endocrinologist will order further tests to assess its nature and potential risks.

The following steps may be taken when diagnosing a thyroid incidentaloma:

  • Medical history: your endocrinologist will review your medical history and discuss any existing health conditions.
  • Physical examination: a physical exam through palpations may reveal signs such as an enlarged thyroid gland.
  • Imaging tests: further imaging studies, such as an ultrasound, may be conducted to evaluate the size, location, and characteristics of the thyroid incidentaloma.
  • Fine needle aspiration (FNA): if the nodule appears suspicious, your doctor may recommend a fine needle aspiration biopsy. This involves using a thin needle to collect a tissue sample from the nodule for laboratory analysis.
  • Blood tests: blood tests to check thyroid function, including TSH, T3, and T4 levels, are often performed to assess thyroid health.
  • Follow-up monitoring: follow-up appointments and imaging may be scheduled to track any changes in the thyroid incidentaloma.
fine needle aspiration
Fine needle aspiration is commonly used to diagnose and treat thyroid incidentaloma

What are the treatment options for thyroid incidentaloma in Singapore?

Treatment for thyroid incidentalomas in Singapore depends on several factors, including the size, characteristics, and potential risks associated with the growth.

Some possible treatment approaches for thyroid incidentalomas include:

  • Observation: small, non-suspicious incidentalomas often require no immediate treatment. Your endocrinologist may recommend periodic monitoring through ultrasound to track any changes.
  • Fine needle aspiration (FNA): if the incidentaloma appears suspicious, an FNA biopsy
    (link to service page) can be conducted to extract a tissue sample for evaluation. This helps determine if the nodule is benign or malignant.
  • Thyroid hormone suppression: in some cases, thyroid hormone replacement therapy may be prescribed to suppress the growth of benign nodules.
  • Surgery: surgical removal of the thyroid nodule or a part of the thyroid gland may be necessary if the growth is causing symptoms, is large, or is determined to be cancerous.
  • Radioactive iodine treatment: if a thyroid incidentaloma is cancerous or if there is a risk of thyroid cancer, radioactive iodine therapy might be recommended post-surgery to destroy any remaining cancer cells.

Your treatment plan will be individualised based on the specific characteristics of the thyroid incidentaloma and any associated health risks. It is important to consult with your endocrinologist for a thorough evaluation and personalised guidance on the best course of action for your case.

Frequently Asked Questions

What are the potential risks associated with thyroid incidentalomas?

The potential risks associated with thyroid incidentalomas include the possibility of thyroid cancer, impact on thyroid function, and, in some cases, discomfort or compression of nearby structures. Regular monitoring is essential.

Can a benign thyroid incidentaloma turn cancerous?

Yes, while benign thyroid incidentalomas are typically non-cancerous, there is a small risk of malignancy. Regular medical evaluation and monitoring are essential to detect potential changes.

What should I do if I discover a thyroid incidentaloma?

If you discover a thyroid incidentaloma, consult your endocrinologist as soon as possible. They can assess the nodule, recommend appropriate tests, and develop a personalised management plan.

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Reyaz Moiz

Dr Reyaz Singaporewalla
Senior Consultant Endocrine and General Surgeon

MBBS (Bom), MS (Surg), DNB (Surg), FRCS (Edin), MMed (Singapore), FRCSEd.