Thyroid & Parathyroid
The thyroid gland is a butterfly-shaped organ located in the front of the neck, just over the windpipe. It produces iodine-containing hormones which regulate the rate at which body cells use energy and produce heat.
The growth and development of all the body’s tissues are dependent on the thyroid gland’s proper functioning. If the thyroid gland is either overactive or underactive, it can create health problems.
Thyroid surgery is indicated in thyroid cancer, enlarged thyroid gland (goitre), Grave’s disease, thyroid nodules, and occasionally in hyperthyroidism.
Thyroid surgery may involve complete or partial removal of thyroid gland which depends upon the type and severity of the condition.
- Total thyroidectomy – It involves removal of entire thyroid gland. It is done to treat thyroid cancer and multinodular goitre.
Lumpectomy or biopsy – It is the removal of small part of the thyroid gland. It is done to check if the thyroid nodules are cancerous.
- Thyroid lobectomy – It involves removal of lobes of the thyroid gland. It is performed if the nodules are located in one of the lobes.
- Subtotal thyroidectomy – It removes the major part of the thyroid gland leaving behind the some tissues on both sides of thyroid gland. It is done to remove tumour in thyroid gland, treat hyperthyroidism, and reduce the size of the enlarged thyroid gland.
- Near-total thyroidectomy – It removes the thyroid gland leaving behind some amount of enlarged thyroid tissue on one side of the thyroid gland. It is indicated in patients who have thyroid cancer, large goitre, and hyperthyroidism caused by Graves’ disease.
Thyroid cancer occurs when abnormal cells within the thyroid gland grow in an uncontrolled way. The thyroid is a gland located at the base of the throat near the windpipe. It produces hormones that help control the body’s heart rate, temperature and metabolism and the amount of calcium in the blood.
There are four main types of thyroid cancer. These are named after the cell type in which the cancer first develops. papillary thyroid cancer is the most common type of thyroid
- follicular thyroid cancer
- medullary thyroid cancer
- anaplastic thyroid cancer (rare).
The most common symptoms of thyroid cancer are:
- a lump or swelling in the throat
- difficulty breathing or shortness of breath
- difficulty swallowing – this is called dysphagia
- a hoarse voice or a cough that doesn’t go away
- enlarged lymph nodes in the neck.
There are a number of conditions that may cause these symptoms, not just thyroid cancer. If any of these symptoms are experienced, it is important that they are discussed with a doctor.
A risk factor is any factor that is associated with an increased chance of developing a particular health condition, such as thyroid cancer. There are different types of risk factors, some of which can be modified and some which cannot.
It should be noted that having one or more risk factors does not mean a person will develop thyroid cancer. Many people have at least one risk factor but will never develop thyroid cancer, while others with thyroid cancer may have had no known risk factors. Even if a person with thyroid cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease.
While the causes of thyroid cancer are not fully understood, there are a number of factors associated with the risk of developing the disease. These factors include:
- exposure to radiation
- a family history of thyroid disease or thyroid cancer
- certain genetic conditions, such as familial medullary thyroid cancer, multiple endocrine neoplasia type 2A syndrome, and multiple endocrine neoplasia type 2B syndrome.
A number of tests may be performed to investigate symptoms of thyroid cancer and confirm a diagnosis. Some of the more
common tests include:
- a physical examination
- examination of a blood sample
- imaging of the thyroid, which may include ultrasound, computed tomography (CT) scan or magnetic resonance imaging (MRI)
- internal examination of the voicebox using a laryngoscope – a thin tube with a light on the end of it
- taking a sample of tissue (biopsy) from the thyroid gland for examination under a microscope.
Treatment and care of people with cancer is usually provided by a team of health professionals – called a multidisciplinary team.
Treatment for thyroid cancer depends on the stage of the disease, the severity of symptoms and the person’s general health. Treatment options can include surgery to remove part or all of the thyroid gland, and radiotherapy (including radioactive iodine therapy), chemotherapy, and/or targeted therapies to destroy cancer cells.
Research is ongoing to find new ways to diagnose and treat different types of cancer. Some people may be offered the option of participation in a clinical trial to test new ways of treating thyroid cancer.
People often feel overwhelmed, scared, anxious and upset after a diagnosis of cancer. These are all normal feelings.
Having practical and emotional support during and after diagnosis and treatment for cancer is very important. Support may be available from family and friends, health professionals or special support services.
In addition, State and Territory Cancer Councils provide general information about cancer as well as information on local resources and relevant support groups. The Cancer Council Helpline can be accessed from anywhere in Australia by calling 13 11 20 for the cost of a local call.
More information about finding support can be found on the Cancer Australia website www.canceraustralia.gov.au
Located behind the thyroid gland are four tiny parathyroid glands. These make hormones that help control calcium and phosphorous levels in the body. The parathyroid glands are necessary for proper bone development. In response to too little calcium in the diet, the parathyroid glands make parathyroid hormone, or PTH, that takes calcium from bones so that it will be available in the blood for nerve conduction and muscle contraction.
If the parathyroids are removed during a thyroid operation, low blood calcium will result in symptoms such as irregular heartbeat, muscle spasms, tingling in the hands and feet, and possibly difficulty breathing. A tumour or chronic illness can cause too much secretion of PTH and lead to bone pain, kidney stones, increased urination, muscle weakness, and fatigue.
Parathyroid surgery is done to treat parathyroid problems such as hyperparathyroidism, enlarged parathyroid glands (parathyroid hyperplasia), and benign tumour (adenoma).
- If all the four parathyroid gland are enlarged, your surgeon removes the major part of parathyroid gland leaving behind a part of the gland in place.
- If one of the parathyroid gland is affected by adenoma, your surgeon will only remove the affected gland leaving behind the remaining unaffected glands.
- National Cancer Institute. Thyroid cancer treatment (PDQ) – patient version. Available from http://www.cancer.gov/cancertopics/pdq/treatment/thyroid/Patient. [Accessed July 2012].
- Brennan M, French J. Thyroid lumps and bumps. Australian Family Physician 2007; 36(7): 531–536.