Thyroid Cancer or Just Goitre? How to find out, as advised by a Doctor
The thyroid is a butterfly shaped gland in the throat, responsible for a variety of endocrine-related processes in the body — from hormone production to regulating our metabolism.
Goitre is a condition where the thyroid gland becomes abnormally large, causing discomfort and difficulty swallowing and breathing. It presents as visible swelling in the base of the neck, and can even cause thyroid dysfunction. How do we know if what we’re experiencing is just goitre, or something more serious, like thyroid cancer?
In this article, Thyroid, Head & Neck Surgeon, Dr Tan Ngan Chye, walks us through everything we need to know to tell the difference between the two, and how to treat it. Read on to find out more!
Goitre: Not just an iodine deficiency
Contrary to popular belief, goitre isn’t just caused by an iodine deficiency, and it can be caused by a variety of factors — from dietary deficiencies to autoimmune conditions. The most common causes of goitre include:
Iodine deficiency is the most common cause for goitre worldwide.
Iodine deficiency
The most common cause for goitre is iodine deficiency. This is because iodine is essential for thyroid hormone production, and the thyroid gland enlarges in an attempt to capture more iodine. Iodine supplements or consuming iodine-rich foods, such as iodised salt, seafood and seaweed could help increase your dietary iodine intake.
Autoimmune disorders
Certain autoimmune disorders, where the body mistakenly attacks healthy cells, can lead to various thyroid disorders, such as:
Graves’ disease – Graves’ disease is an autoimmune disorder where the body attacks the thyroid, leading to hyperthyroidism and goitre development [1, 4].
Hashimoto’s disease – Hashimoto’s thyroiditis is also an autoimmune disorder where the body produces antibodies that attack the thyroid cells.
Medications or environmental factors
Some types of medications (e.g. lithium), or exposure to environmental toxins can, in some cases, cause thyroid enlargement.
Hormonal changes
Temporary hormonal shifts, such as during pregnancy or puberty, can increase thyroid activity and lead to a goitre.
Infection or inflammation
Thyroiditis, or inflammation or infection of the thyroid, can cause swelling of the thyroid gland.
Genetic predisposition
A family history of thyroid issues or other genetic conditions can increase an individual’s risk of developing goitre as well.
Thyroid cancer
Thyroid cancer can cause goitre when malignant cells proliferate, causing abnormal growth of thyroid tissue.
It can be confusing to identify the different types of goitres, hence it is always recommended to seek medical attention for a proper diagnosis.
Thyroid Cancer vs. Goitre
Thyroid cancer is caused by the abnormal growth of malignant cancer cells in the thyroid gland. There are 4 main types of thyroid cancer:
Papillary thyroid cancer (PTC) – The most common type of thyroid cancer, which is derived from the follicular cells of the thyroid. These cancers are also likely to spread via lymph nodes [6].
Follicular thyroid cancer (FTC) – Thyroid cancer derived from follicular cells which are more aggressive than PTC, and are more likely to spread via the bloodstream [6].
Medullary thyroid cancer (MTC) – Cancers derived from neuroendocrine cells or parafollicular cells [7, 8]. MTCs can be genetically inherited in multiple endocrine neoplasia (MEN) type 2 syndrome [8].
Anaplastic thyroid cancer (ATC) – This is a rare and aggressive type of thyroid cancer. ATCs are thought to be linked to genetic mutations such as BRAF, RAS, and TP53 genes [9].
Unfortunately, the appearances of thyroid cancers and goitres are similar, and it can be a challenge to differentiate the rare cases of thyroid cancers from the more common incidences of goitres. Most clinicians diagnose thyroid cancers from nodules found on the thyroid, whereby about 5% of thyroid nodules found are malignant [5, 10].
Oftentimes, goitres and thyroid cancers can appear similar, especially with nodular goitres. Here are some key differences:
Feature
Goitre
Thyroid Cancer
Cause
Can be caused by multiple factors, such as insufficient dietary iodine, autoimmune disorders, or underactive thyroid activity. Goitres can also have no known cause.
Caused by the presence of malignant (cancerous) thyroid cells caused by genetic mutation or radiation.
Growth
General enlargement of thyroid, can be smooth or nodular/multinodular.
Often presents as a single, firm, and rapidly growing lump.
Key symptoms
General enlargement of thyroid glandChanges in metabolism or energy levelsMay lead to hypothyroidismFatigueSensitivity to coldDry skin ConstipationMuscle weaknessMay lead to hyperthyroidismWeight lossRapid heart rateSensitivity to heatExcessive sweatingTremorsIncreased appetiteMuscle weaknessFrequent bowel movementsDysregulated menstrual cycleHigh blood pressure
Thyroid nodule or lump on your neckSwollen lymph nodes in your neckNausea and vomitingUnexpected weight loss
Progression
Goitres develop slowly over time.
Thyroid cancer may have a more rapid progression, over weeks or months.
In general, goitres may present more diverse symptoms that accompany thyroid enlargement, this includes metabolic and hormonal symptoms. While a lump on the neck with swollen lymph nodes may indicate metastasis of the thyroid cancer. It is always recommended to consult a doctor to get a proper and complete diagnosis.
How can my doctor tell the difference?
Your doctor will perform several tests to identify a malignant growth from a benign thyroid enlargement [1]:
Thyroid function test – This test checks for thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) levels in the patient. This may identify whether goitres are euthyroid or toxic. Calcitonin level can also be evaluated if MTC is suspected.
Ultrasonography – Ultrasonography is an imaging test that allows doctors to differentiate between possibly malignant growths and non-malignant ones. The doctor will usually look for features such as irregular borders of the growth, vascularisation, hypoechogenicity (refers to how well the tissues send back ultrasound waves, this can be an indication of tissue density and composition), lymph node metastasis, and microcalcifications.
Fine needle aspiration cytology (FNAC) – This test involves taking tissue samples from the thyroid with the help of ultrasound. The tissue sample is then sent for laboratory tests to identify the presence of cancerous markers or features.
Fine needle aspiration cytology is used to identify thyroid cancer from thyroid tissue samples.
Risk factors of thyroid cancer
In general, thyroid cancers and goitres share certain similar risk factors such as:
Gender – Similar to goitres, thyroid cancer is more common in women than in men.
Age – Thyroid cancer risk increases with age.
Family history and genetics – Familial history of thyroid issues or thyroid cancers, as well as genetic conditions like multiple endocrine neoplasia type 2 can increase the risk of thyroid cancer.
Radiation exposure – Radiation exposure to the head and neck region, such as from radiotherapy for head and neck cancers, or from occupational exposure.
Iodine imbalance – Low iodine diet can increase the risk of thyroid cancer.
Excess body weight and obesity – Studies have shown a clear relationship between having excess body weight and thyroid cancer [11].
However, thyroid cancers may have specific causes such as MEN type 2 syndrome and genetic mutations such as BRAF and RAS genes.
An enlarged thyroid gland could mean anything from a benign goitre to thyroid cancer, making a proper diagnosis crucial to getting the right treatment.
When do I need to see a doctor?
Pay attention to your body. If you experience any of the symptoms that concern you, let your doctor know so that they may address them and advise you. Visit a doctor if you experience the following:
You have a lump or swelling on your throat that persists or changes in size – This can be due to nodular goitres, which have the potential to be diagnosed as thyroid cancer.
Signs of thyroid dysfunction – Symptoms of thyroid dysfunction include:
abnormal changes in metabolism and energy levels
sensitivity to temperature extremes
sudden weight loss
increased sweating
tremors
mood changes, irritability or depression
hoarseness or changes in your voice
Resistance when swallowing
Swelling of the neck lymph nodes – Lymph node swelling around the neck can be caused by bacterial or viral infections, thyroid issues, or cancer.
Hypothyroidism – Hypothyroidism refers to the thyroid not making enough thyroid hormones, this can affect your metabolism, energy levels, and mood, among other issues.
Hyperthyroidism – Hyperthyroidism is the opposite of hypothyroidism, where the thyroid is overactive in producing hormones. This is typically observed in toxic types of goitres.
Breathing and swallowing difficulties – Obstruction of the throat by the enlarged goitres can affect breathing and swallowing.
Summary
It can be challenging for individuals to distinguish the difference between a goitre and thyroid cancer, and knowing their key differences is important — but sometimes, professional medical advice is necessary. Your doctor can use diagnostic tools to accurately determine whether the swelling in your throat is due to benign goitre or thyroid cancer, because we can’t rely on visual or symptomatic queues alone.
If you’re experiencing any of the above, consult your doctor. Early evaluation and timely treatment can make all the difference in achieving optimal medical outcomes. Schedule a consultation with us today for a comprehensive diagnosis and personalised treatment plan.
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