Updated: Aug 13, 2021
Welcome back to our TGIF Dr Euan blog!
It's great to have you back as we prepare for our upcoming National Day celebration / ceremonial march past next Monday at the Marina Bay floating platform.Even though it will be a muted celebration this year due to the COVID pandemic, yet we can still celebrate with our family at home and virtually as a nation 🇸🇬 !
Today, let's have a look at another topic which you dear readers have requested for discussion: THYROID LUMPS
Q: What is the Thyroid Gland?
The thyroid gland is a small organ that is located in the front of the neck, wrapped around the windpipe (trachea). It's shaped like a butterfly, smaller in the middle with two wide wings that extend around the side of your throat. The thyroid is an endocrine gland that produces various hormones essential for our body's metabolism.
Q: What does the Thyroid Gland do?
The thyroid gland secretes several hormones, collectively called thyroid hormones. The main hormone is thyroxine, also called T4. Thyroid hormones act throughout the body, influencing metabolism, growth and development, and body temperature. During infancy and childhood, adequate thyroid hormone is crucial for brain development. There are also hormones which regulate calcium levels in your bloodstream which maintain healthy heart and bones. These are produced by the para-thyroid glands which are intimately associated to the thyroid gland / lobes.
Q: Where is the thyroid gland located in our body?
The thyroid is a butterfly-shaped gland that sits low on the front of the neck. Look at your neck in the mirror. Your thyroid lies below your Adam’s apple, along the front of the windpipe. The thyroid has two side lobes, left & right, connected by a bridge (the isthmus) in the middle.
When the thyroid is its normal size, you cannot feel it. So it is generally abnormal if you can feel the thyroid gland, that is, enlarged , either uniformly (called a goitre) or with a lump (called a nodule)
Brownish-red in colour, the thyroid gland is richly supplied with blood vessels. Certain nerves important for voice quality also pass through or very close to the thyroid gland.
Q: Why do we get thyroid lumps or nodules?
The exact cause is unknown, but there are certain risk factors eg if you are female, with a positive family history of thyroid disease or have certain syndromes eg MEN (Multiple Endocrine Neoplasia) syndrome, then you are at a higher risk.
Q: What are thyroid nodules? A thyroid nodule is a lump that can develop in your thyroid gland. It can be solid or filled with fluid (called a cyst). You can have a single nodule or a cluster of nodules. Thyroid nodules are relatively common and, fortunately, rarely cancerous.
Thyroid nodules are classified as cold, warm, or hot, depending on whether they produce thyroid hormones or not: Cold nodules don’t produce thyroid hormones. Warm nodules act as normal thyroid cells. Hot nodules can overproduce thyroid hormones.
More than 90 percent of all thyroid nodules are benign (non-cancerous). Most thyroid nodules are small and cause few symptoms. It is possible for you to have a thyroid nodule without even knowing it. Nowadays, with many health screening packages offering Ultra Sound Thyroid scans, we are picking up very small thyroid nodules, < 5 mm in size. At that size, we will usually monitor their growth rate / pattern over time. Many do not grow, or grow very slowly.... it is the rapidly growing ones that cause concern.
Unless it becomes large enough to press against your windpipe, you may never develop noticeable symptoms. Many thyroid nodules are discovered during imaging procedures (such as US, MRI or CT scan) done to diagnose other conditions eg Cervical Spondylosis (stiff neck), and are reported incidentally by the reporting radiologist.
In everyday life, our thyroid gland regulates many vital body functions; here is an info-graphic that shows how the thyroid gland functions in a healthy individual:
Q: What do these hormones do in our body?
Q: What are the symptoms of a thyroid nodule?
As most nodules are small, you may have a thyroid nodule and not have any symptoms. But if the nodule gets large enough, you may develop:
an enlarged thyroid gland, known as a goitre; this is a more generalised swelling of the thyroid gland, but it may also contain many smaller nodules, which then is called a Multi-Nodular Goitre (MNG)
pain / discomfort at the base of your neck
If your thyroid nodule is producing excess thyroid hormones, you may then develop symptoms of hyperthyroidism, such as:
rapid and/ or irregular heartbeat (tachycardia or fibrillation)
unexplained weight loss
difficulty sleeping / insomnia
anxiety, irritability and nervousness
In some cases, thyroid nodules develop in people with Hashimoto’s thyroiditis. This is an autoimmune thyroid condition (more common in ladies) that increases the risk of developing an under-active thyroid (hypothyroidism). Symptoms of hypothyroidism are related to insufficient thyroid hormone and include:
persistent fatigue / tiredness
unexplained weight gain
sensitivity to cold
dry skin and hair
Q: What should I do if I discover I have a thyroid lump?
Well, generally, you should seek a medical consultation, whereby your doctor will take a detailed history and perform a medical examination, looking out for any signs of hyper- or hypo-thyroidism, as outlined above.
If there are any suspicious features or concerns, your GP will refer you to see an ENT or a Head & Neck surgeon / specialist for further evaluation. Oftentimes, your GP will arrange for:
Ultra-sound Scan of the Thyroid
Thyroid Function (blood hormone levels) Test
At the Specialist Clinic, we will confirm the history and examination, review your Ultra-sound scan report and most likely, arrange for an Ultra sound guided Fine Needle Aspiration for Cytology (FNAC) biopsy. This FNAC result usually takes between 3 to 5 days to process and will provide further detailed information on the nature of the cell types seen in the nodule.
Q: How is the Fine Needle Aspiration for Cytology or FNAC done?
FNAC biopsies are done in a clean / sterile manner with the use of topical and/ or local anaesthesia to make the procedure as painless and comfortable as possible for you.
The FNAC biopsy is done under direct ultra-sound guidance to ensure that the needle is in the correct optimal location to get a good yield of cells; mostly we will have an onsite cyto-technician to check if the biopsy is adequate and if we need to repeat the aspiration. Nowadays, it is a very safe and accurate procedure, usually performed by an experienced radiologist / endocrinologist with highly specialised training. There are also regular audits to review the sampling and the results of such FNAC procedures so rest assured that you are in good hands.
Here is an info-graphic on what the FNAC procedure involves:
Once the on-site cyto-technician confirms an adequate and representive yield of thyroid cells on the FNAC biopsy, the slides are stained and sent to the cyto-pathology laboratory for more detailed analysis and reporting.
Depending on the FNAC result, your ENT Specialist will then discuss with you the various options or recommendations. It does not mean AUTOMATIC surgery for every thyroid nodule we see in practice eg some turn out to be simple cysts which can be aspirated and / or ablated. At other times, we may choose to monitor the nodule over time with serial ultra-sound scans.
Most of our local thyroid surgeons and specialists follow the Bethesda FNAC grading system. This system provides a high degree of accuracy in helping to guide management decisions and predict outcomes.
The Bethesda system for reporting thyroid cyto-pathology is a grading system with an implied risk of malignancy and recommended clinical management. There are 6 grades in the Bethesda system, ranging from :
III. Follicular lesion of undetermined significance (FLUS)
IV. Follicular neoplasm
V. Suspicious for malignancy
If the thyroid nodule is deemed to be malignant (cancerous) or with a high chance of malignancy, then your ENT Specialist will discuss with you the various modalities of treatment, including hemi/ partial or total thyroidectomy, any neck dissection of lymph nodes and any adjuvant treatment eg Radio Iodine therapy. We may also discuss your case at a multi-disciplinary Head & Neck Tumour Board, especially if the cancer is of a rare or an aggressive nature. All thyroid cancer patients are followed up for life.
We also work closely with our ENDOCRINOLOGY colleagues to manage your thyroid hormonal status to make sure that your hormones keep within the normal / physiologic range, that is, not too high and not too low. This is to ensure that the many important body functions are not impaired and you can live an active & normal life.
So dear readers, today's
Take Home message:
Thyroid lumps are quite common, especially in ladies. Most are small & benign (non-cancerous), up to 90 percent, but some are cancerous (up to 10 percent). If you discover a neck / thyroid lump, it is best to see your GP or ENT Specialist to check it out.
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Thanks for reading this week's blogpost 😊
Meanwhile, have a great National Day weekend! DO get vaccinated and keep COVID safe!