Thyroid Disorders & Thyroid Cancer

About the Thyroid

The Thyroid has an important role to regulate numerous metabolic processes throughout the body.

The Thyroid gland is located below Adam's apple wrapped around the trachea (windpipe) in the front of the neck.

A thin area of tissue in the gland's middle, known as the isthmus, joins the two thyroid lobes on each side. It is butterfly-shaped.

About Thyroid Disorders

The Thyroid’s function is regulated by the brain's hypothalamus.

When Thyroid hormone levels are low, the brain produces a hormone that causes the pituitary gland to release Thyroid Stimulating Hormone (TSH).

Since the Thyroid gland is controlled by the pituitary gland and hypothalamus, disorders of these tissues can also affect thyroid function and cause thyroid problems.

Thyroid disorders are conditions that affect the Thyroid gland and cause dysfunction of the Thyroid gland.

It uses iodine to produce vital hormones. Thyroxine is the primary hormone produced by the gland.

After delivery throughout the body via the bloodstream, a small portion of the Thyroxine released from the gland is converted to triiodothyronine, which is the most active hormone.

Types of Thyroid Disorders

Different Types of Thyroid Disorders affect either the structure or function of the Thyroid Gland.

The most common types of Thyroid Disorders are:

• Hypothyroidism - The underproduction of hormones by the Thyroid gland.
• Hyperthyroidism - The over-production of a hormone by the Thyroid gland.
• Goitre - Abnormal enlargement of the Thyroid gland below Adam's apple.
• Thyroid Nodules - A lump in the Thyroid gland
• Thyroiditis - Inflammation of the Thyroid gland.
• Thyroid Cancer - A cancer of the Thyroid gland

Although the effects of Thyroid Disorders can be unpleasant or uncomfortable, most thyroid problems can be managed well if properly diagnosed and treated.

What are the Causes of Thyroid Disorders?

Thyroid Disorders typically refer to a set of symptoms that are associated with hypothyroidism (an underactive thyroid gland) or hyperthyroidism (an overactive thyroid gland).

Thyroid diseases sometimes result from inappropriate levels of Thyroid-stimulating hormone being produced by the pituitary gland or caused by problems in the thyroid gland itself.

Hypothyroidism

There are different causes of hypothyroidism. The most common cause of hypothyroidism is:

• Hashimoto's thyroiditis is an autoimmune condition where the body makes antibodies that destroy parts of the thyroid gland.

Other causes are:

• Pituitary problems,
• Hypothalamus problems, and
• Congenital hypothyroidism.

Hyperthyroidism

There are different causes of hyperthyroidism. The most common cause of hyperthyroidism is

• Graves' disease is when the immune system produces an antibody that stimulates the entire thyroid gland; this leads to overactivity and higher levels of thyroid hormones.

Other causes are:

• Toxic nodular goitre or toxic thyroid adenoma which are abnormal nodules of tissue in the thyroid, constantly produce thyroid hormones even when they are not needed.
• Secondary hyperthyroidism is caused when the pituitary gland makes too much TSH, leading to over-stimulation
• A pituitary tumour may cause TSH levels to rise or insensitivity disables Thyroid responsiveness
• Thyroiditis inflammation leading to temporary hyperthyroidism or hypothyroidism after

Who are at risk of Thyroid Disorders?

Both hypothyroidism and hyperthyroidism are common conditions that numerous people suffer from.

People at higher risk of Thyroid Disorders include those with:

• a family history of thyroid
• other gland-related conditions,

What are the Symptoms of Thyroid Disorders?

Thyroid Disorders can involve a changing metabolic rate.

• Hair Loss - visible changes in their hair thinning
• Skin Problems - uncharacteristically dry and patchy or more oily and acne-prone.
• Weight Gain - at a high pace without any change in their appetite, lifestyle hypothyroidism.
• Weight Loss - without any change of food consumption (hyperthyroidism)
• Unpredictable Bowel Function - either a low thyroid production creating a slower metabolism, a lazy gut and constipation or, high thyroid production creating a higher metabolism, diarrhoea and/or frequent urge to defecate.
• Swelling of the Neck - a visible neck inflammation due to development of goitre requiring prompt medical investigation.
• Menstrual Problems - changes in menstrual patterns such as increased blood flow and longer cycles (hypothyroidism) or the opposite (hyperthyroidism)
• Depression or Anxiety - mood disturbances, lower brain serotonin levels (hypothyroidism), leading to lethargy or depression, the opposite anxiety, restlessness and excess energy. (hypothyroidism)
• Loss of Libido - decreased sex drive due to lower adrenaline glands
• Change in Sleep Patterns - altered sleep patterns. sluggish and sleepy (hypothyroidism) or alert and sleepless (hyperthyroidism).
• Muscle and Joint Pain - with thyroid malfunction, muscle and joint health are also affected. Frequent aches and pains, muscle weakness that has no obvious explanation and carpal tunnel syndrome a little too often.

Diagnosis of Thyroid Disorders

A thorough medical history and examination is performed. Additional tests may be ordered including;

Pathology Tests

Blood tests are used to

• Measure levels of thyroid hormones
• Measure Thyroid Stimulating Hormone
• Identify antibodies
• General “check up” blood tests in preparation for surgery if required

Radiology Tests

Imaging tests using ultrasound are used to

• Assess the size and characteristics of the thyroid gland including any nodules which may lie within the thyroid itself

Imaging tests using radioactive iodine are used to

• Review the function of thyroid nodules

Imaging tests using CT scan are used to

• Define the extent of enlargement of the thyroid
• Define the extent of lymph node enlargement

Biopsy Tests

Based on the ultrasound findings, if there are nodules within the thyroid or adjacent lymph nodes which appear abnormal or suspicious a biopsy is usually recommended

• Fine Needle Aspiration (FNA)- this approach uses a needle to aspirate a thyroid gland tissue sample is taken.
• Surgical biopsy – If there are concerns raised by the FNA then surgery may be recommended to make a definitive diagnosis. This can involve removing a portion (usually half) of the thyroid or the lymph node in question

Thyroid Cancer

What is thyroid cancer?

Thyroid cancer is an abnormal growth of the cells of the thyroid gland, a butterfly-shaped gland located in front of your neck just below the voice box (larynx). The thyroid gland secretes hormones that help regulate the body’s metabolism. Thyroid cancer is more common in women than men. People who are exposed to high levels of radiation to the neck and have a family history of thyroid cancer and goitre (enlargement of thyroid gland) are at a higher risk of developing thyroid cancer.

What are the types of thyroid cancer?

There are four types of thyroid cancer:

• Papillary thyroid cancer – It is the most common type of thyroid cancer and usually spreads slowly. This can be cured especially if early diagnosis is made.
• Follicular thyroid cancer – Cancer that develops in the follicular cells and usually spreads slowly. Like papillary thyroid cancer, it can be cured with early diagnosis.
• Medullary thyroid cancer – Cancer that arises from C cells of the thyroid gland. It produces abnormally high amounts of the hormone, calcitonin. It is commonly associated with genetic conditions like Multiple Endocrine Neoplasia ( MEN) and can often spread to lymph nodes or other organs within the body
• Anaplastic thyroid cancer – Aggressive thyroid cancer that grows and spreads quickly to other parts of the body. It is the least common type but the most aggressive form of thyroid cancer.

What are the signs & symptoms of thyroid cancer?

As the cancer develops, you may notice a lump or swelling in front of your neck, pain in the neck or throat, difficulty in swallowing or breathing, cough, and changes or hoarseness in your voice.

How is thyroid cancer diagnosed?

Your doctor will recommend a treatment plan based on the results of diagnostic tests such as blood tests, ultrasound of the thyroid gland, thyroid biopsy, thyroid scan and laryngoscopy.

• Ultrasound of the thyroid: It uses sound waves to create images of your body. This test uses a lubricating gel and a transducer rubbed over the neck to look at the size and texture of the thyroid gland. This test can tell whether a nodule is a fluid-filled cyst, or a mass of solid tissue.
• Biopsy: Fine Needle Aspiration (FNA) is performed as a way of sampling any suspicious nodules or masses seen on imaging. If a definitive diagnosis can’t be made, surgery is often recommended
• Blood tests: blood tests to check the levels of certain hormones and other thyroid cancer markers.
• Laryngoscopy: It is an examination of the larynx (voice box) performed by inserting a small camera through the nose and into the back of the throat.
• Computed tomography (CT) scan: this is occasionally used to assess spread of cancer locally and to the adjacent lymph nodes.

What are the treatment options for thyroid cancer?

Depending upon the type of thyroid cancer present, your doctor may choose one or more of the following thyroid cancer treatment options:

• Surgery: Generally, surgery is the most common treatment for thyroid cancer. Total thyroidectomy is a surgical procedure to remove all the thyroid gland. Hemithyroidectomy is a surgery to remove part / half of the thyroid gland. Your doctor may also remove the lymph nodes if the cancer has spread to the lymph nodes.
• Radioactive iodine: Radioactive iodine comes in a pill or liquid that you swallow. It has a small amount of radiation and can destroy thyroid tissue including thyroid cancer cells.
• Radiation therapy: This method uses high beam radiation to destroy the cancer cells.
• Chemotherapy: It is a type of cancer treatment that uses drugs to destroy cancer cells. Chemotherapy is used in patients with cancer that cannot be treated with surgery or is unresponsive to radioactive iodine, as well as for patients with cancer that has spread to other parts of the body.

What is the postoperative care after thyroid cancer surgery?

Most patients are able to go home the day after surgery and are able to return to work within 1-2 weeks.

During this period pathology results will be received which helps determine prognosis and guide decisions about further treatment such as radioactive iodine ( RAI)

Follow up after treatment includes regular reviews by the treating doctor combined with blood tests and ultrasound of the neck.

Treatments for Thyroid Disorders

Treatment depends on the diagnosis and nature of the disease. Common treatments include:

• Medication
• Radioactive Iodine treatment
• Thyroid Surgery (Thyroidectomy)
• Chemotherapy (rare)

Medication Treatment for Thyroid Disorders

Oral medications used in treating Thyroid disorders are:

• Beta-blockers: to block hyperthyroidism response decrease tremor, nervousness, and agitation
• Antithyroid Drugs: to block thyroid hormone synthesis
• Iodide: to inhibit the release of thyroid hormone for hyperthyroidism with an antithyroid drug

Radioactive Iodine Treatment for Thyroid Disorders (RAI)

This treatment takes several months to work by scarring down the thyroid gland, resulting in a smaller-sized gland, often accompanied by hypothyroidism.

The iodine goes to the thyroid tissue and the radiation destroys it. It may also be used for cancer that spreads to nearby lymph nodes, spreads to other parts of the body, or returns.

The thyroid gland and most thyroid cancers absorb iodine. Radioactive Iodine Ablation (RIA) is used to destroy any thyroid tissue that’s left after a thyroidectomy.

Thyroid Surgery (Thyroidectomy)

Surgery can be used to remove a large goitre or a hyperfunctioning nodule within the gland. Surgery is necessary when there is a possibility of thyroid cancer.

Read more about Thyroidectomy

If the thyroid gland is removed entirely, the individual will need to take synthetic thyroid hormone for life. Usually when only half the thyroid is removed ( hemithyroidectomy ) patients do not require medication.

Thyroid surgery can also be used in Graves' Disease and was the treatment of choice prior to RAI therapy and anti-thyroid medications.

External Beam Radiation for Thyroid Disorders

X-ray therapy uses radiation to destroy cancer cells. It is targeted to protect other organs and can last several weeks.

What is the Prognosis of Thyroid Cancer?

The most common types of Thyroid Cancer is usually very treatable and associated with good outcomes and high levels of survival. What cancer means for the individual depends on a variety of factors including general health of the patient, pathology results and response to treatment.