Thyroid nodules are common in the general population. Malignant thyroid tumours are less common. Thyroid nodules are discovered through a variety of ways including: by your doctor during a routine visit, by feeling a bump in your neck and by chance after an ultrasound, CT, MRI or PET scan of the neck. At times thyroid cancer is not detected until it has spread to the lymph nodes in the neck.
It is estimated that about 5% of thyroid nodules that are detected on exam are malignant in females and >5% of thyroid nodules are malignant in males.
Symptoms of thyroid cancer are not usually experienced until the tumour has progressed to a later stage, since thyroid cancer is not always easily felt in the neck. A bump that can be felt in the middle of the neck (where a bow tie is worn) is often a sign of a thyroid tumour and should be examined by your doctor. A large thyroid nodule or a thyroid nodule that enlarges rapidly are commonly caused by benign etiologies. Nevertheless, seeking medical advice is important in both scenarios.
When thyroid cancer progresses it can press on the windpipe (trachea) or esophagus, and lead to shortness of breath and difficulty swallowing. Enlarged lymph nodes in the neck, coughing and hoarseness can also be signs of thyroid cancer. It is important to keep in mind that these symptoms are more commonly associated with less serious medical conditions, for example a cold. Nevertheless, consulting your physician is important when these symptoms develop, especially if they persist.
The exact cause of many thyroid cancers have not yet been clearly elucidated. Females are more commonly affected than males. There are risk factors that can be associated with the development of thyroid cancer.
Genetic Risk Factor
Medullary thyroid cancers are sometimes due to an inherited genetic change. When other tumours in the body occur concurrently with medullary thyroid cancer, such as a pheochromocytoma of the adrenal gland, a syndrome called multiple endocrine neoplasia (MEN) type 2 may be suspected. Other types of thyroid cancers, such as papillary thyroid cancer may run in families. The exact mechanism is not yet fully understood. Certain mutations in thyroid tumors, such as BRAF V600E, are associated with thyroid cancer as well.
Radiation Risk Factor
Individuals who have been exposed to radiation (radiation treatment for cancer in the past, exposure to radiation from a nuclear reactor…etc) are at a higher risk of developing thyroid cancer. This is one of the only well established environmental risk factor for thyroid carcinoma.
There are different types of thyroid cancers that arise from different cells in the thyroid gland. Papillary carcinoma is the most common malignant thyroid tumour, followed by follicular carcinoma. Both together are referred to as differentiated thyroid tumors.
Anaplastic thyroid carcinoma occurs much less often. Like the two differentiated thyroid tumours, it starts from the thyroid hormone-producing cells of the gland. It is a very aggressive form of thyroid cancer.
Medullary thyroid cancer, which is also rare, has its origin in the calcitonin-producing C cells. An increased serum calcitonin level may be suspicious for medullary carcinoma.
At ENT Specialty Group, our team of experienced thyroid surgeons and endocrinologists have expertise in the investigation and management of thyroid nodules. We understand the anxiety associated with discovering a thyroid tumour and the importance of a proper treatment.
This may involve a thyroid morphology ultrasound examination, an ultrasound guided thyroid biopsy (USFNA), and when indicated, molecular testing of thyroid nodules (Afirma, ThyroseqV3, ThyGenx/Thyramir). When thyroid surgery is required it is performed at one of the McGill University hospitals (Jewish General Hospital, MUHC / Glen site Royal Victoria Hospital, MUHC / Montreal General Hosptial), McGill University affiliated hospitals, or University of Montreal affiliated hospitals. Our team also has extensive experience with the management and surgery of the parathyroid glands for elevated calcium levels (hypercalcemia).
Our aim is to provide patients with compassion, attention, and timely care from the moment that a thyroid nodule is discovered until treatment is no longer required.
For differentiated thyroid cancer, when it is identified and treated early, the prognosis is usually excellent. Surgery is the mainstay of treatment (thyroidectomy, partial or total). At times, radiation treatment in the form of radioactive iodine is recommended in specific instances. Treatments such as chemotherapy or external beam radiation are rarely indicated. The tissue subtype, the stage of the cancer, the molecular mutation and other factors play a role in the treatment.