Thyroid Cancer Symptoms

What Is Thyroid Cancer?

When malignant cells start forming in tissues of the thyroid gland, the disease is called thyroid cancer. The thyroid gland is found at the base of the throat, near the windpipe. It has two lobes, left and right, which are connected with a thin piece of the gland called an isthmus. The thyroid gland itself is shaped like a butterfly.

There are two main types of cells present in the thyroid gland: [¹] [²]

Follicular cells: Follicular cells present in the thyroid gland use iodine in the blood to produce and secrete thyroid hormones. Thyroid hormones control body temperature, heart rate, and metabolism of the body. An excess of thyroid hormones in the body causes nervousness, hunger, irregular heartbeat, and weight loss, a condition known as hyperthyroidism. Having too few thyroid hormones results in a feeling of tiredness and gaining weight, which is known as hypothyroidism.
C cells: The primary function of C-cells in the thyroid is to secrete calcitonin and some neuroendocrine peptides like CGRP, somatostatin, serotonin, etc. Calcitonin acts against the parathyroid hormone and decreases the calcium levels in the blood. [³]

Thyroid cancer is the most common type of endocrine cancer and results when the cells grow out of control. Thyroid cancer interferes with the functioning of the thyroid gland, and if left untreated, cancer can spread beyond the thyroid gland into other parts of the body.

Thyroid cancer is a rare type of cancer that makes up only 2.3 percent of all new cancer cases. [⁴] This type of cancer is mostly diagnosed in younger individuals as compared to other adult cancers. Thyroid cancer most often appears in White people, and Black people have the lowest rate of developing this type of cancer. [⁵]

Thyroid cancer can be divided into many types and subtypes of cancer, with well-differentiated thyroid cancers having a good prognosis. Thyroid cancer is mostly asymptomatic until it progresses to an advanced stage. A biopsy is an important test to confirm the diagnosis and determine the stage of thyroid cancer.

Types of Thyroid Cancer

Thyroid cancers can be one of the two following kinds; [¹]

Differentiated Thyroid Cancer

These include;

Well-differentiated tumors: Papillary thyroid cancer and follicular thyroid cancer.
Poorly differentiated tumors: Anaplastic thyroid cancer.

Medullary Thyroid Cancer

MTC is a rare type of thyroid cancer (accounts for up to 4% of all cases) and develops when the C-cells become malignant and grow out of control. [⁶]

The four main types of thyroid cancer are; [⁷] [⁸]

Papillary Thyroid Carcinoma

Papillary thyroid cancer (PTC) develops from follicular cell differentiation, and it also carries the best prognosis. This type of thyroid cancer grows slowly and is usually found as an irregular solid mass in one lobe of the gland. A smaller percentage of papillary thyroid cancer (almost 10 to 20 percent) appears in both lobes. PTC is the most common type of thyroid cancer, but it has the characteristic of invading adjacent lymphatic structures. [⁹] It is more common in women and diagnosed in younger individuals.

Follicular Thyroid Cancer

Follicular thyroid cancer is another well-differentiated thyroid cancer, and the second most prevalent type of thyroid cancer (accounts for 10 to 15 percent of all cases.) [¹⁰] Follicular thyroid cancer starts developing in follicular cells but rarely does it invade lymph nodes. This type of thyroid cancer is also often curable if found at an early stage and in individuals younger than 50 years of age.

Medullary Thyroid Cancer

Medullary thyroid cancers account for only 2 to 3 percent of all thyroid cancer cases. It is the rarest type of thyroid cancer, but 25% of medullary thyroid cancer cases run in families. The families carry a genetic change in RET gene that results in a condition known as multiple endocrine neoplasia type 2 (MEN2.) [⁶] MTC can spread to other parts of the body, but if it is diagnosed and treated early, it can be controlled.

Anaplastic Thyroid Cancer

Anaplastic thyroid cancer is an undifferentiated thyroid cancer which is a rare but highly aggressive tumor. It accounts for 2% to 3% of all thyroid gland cancers and has a poor prognosis. Anaplastic thyroid cancer can result in a metastatic spread, which makes it a highly deadly disease. [¹¹] This type of thyroid cancer is more common in women and is mostly diagnosed in older individuals.

How Is Thyroid Cancer Diagnosed?

The following tests are used to diagnose and determine the stage of thyroid cancer:

Physical examination
Blood tests monitor thyroid hormone levels, TSH in blood, and levels of Tg and TgAb.
Ultrasound
Biopsy
CT scan
Molecular testing on tumor sample. [¹⁴]

Thyroid Cancer Staging

The TNM staging system classifies thyroid cancer on 3 factors:

T: What is the size and location of the primary thyroid tumor?
N: Has the tumor spread to the lymph nodes?
M: Has the thyroid tumor metastasized to other parts of the body?

Thyroid Cancer has many types, and the TNM stages differ for each of them: [¹²]

Is Thyroid Cancer Hereditary?

Individuals who have a family history of thyroid cancer are at a higher risk of developing the disease. If one or more first-degree relatives or a close family member has thyroid cancer, the risk is very high.

Thyroid cancer can also develop in people who may inherit a faulty RET gene. About 25% of medullary thyroid cancers are inherited. [¹³]

Thyroid Cancer Symptoms

Most thyroid cancers are detected in routine examinations or X-rays and imaging tests. People with thyroid cancer may experience the following symptoms.

A lump in the front part of the neck.
Difficulty swallowing and breathing.
Swollen glands of the neck.
Pain in the throat.
Hoarseness.
A persistent cough.

Sometimes the above symptoms are caused by non-cancerous conditions, like goiter, and sometimes thyroid cancer patients do not show any symptoms at all. But it is recommended to immediately see a doctor as soon as you notice any abnormal signs in your body. [¹⁵]

What Are the Symptoms of Thyroid Cancer?

Thyroid cancer has many different types with different sub-stages, so their symptoms also vary.

Papillary Thyroid Carcinoma

The most predominant thyroid cancer form is PTC, and it shows the following symptoms; [⁹]

Asymptomatic and painless lesion
Hoarseness
Dysphagia
Tracheal compression
Enlargement of regional lymph nodes is possible.

Follicular Thyroid Cancer

The histological and physical symptoms of follicular thyroid cancer include; [¹⁰]

Enlargement of the thyroid gland
Presence of a nodule in both or one of the thyroid lobes.
Presence of hypothyroidism or hyperthyroidism features.

Medullary Thyroid Cancer

The symptoms of medullary thyroid cancer include; [⁶]

A lump in the throat
Hoarseness
Breathing difficulty
MTC can often be asymptomatic for a long time.

Anaplastic Thyroid Cancer

The symptoms of Anaplastic Thyroid Cancer start appearing as; [¹⁶]

A painful, firm mass in the low anterior neck is rapidly growing.
Hoarseness
Dysphagia
Cough
Dyspnea
Vocal cord paralysis.

What Are Some Signs of Thyroid Cancer?

When the symptoms of thyroid cancer start appearing, doctors order certain tests that can confirm the diagnosis of the disease.

Physical Examination

The doctor will examine the size and firmness of the thyroid gland and check for any enlarged lymph nodes. During the examination, the healthcare professionals will also inquire about your medical and family history. If a close relative has thyroid cancer, it puts the suspected individual at a higher risk for this disease.

Imaging Tests

Imagining tests can provide detailed images of the thyroid gland.

An MRI creates cross-sectional pictures of the thyroid gland and differentiates between normal and cancerous tissue.

Ultrasound determines the size of thyroid nodules and determines whether a suspected nodule is solid, which indicates that it may be cancerous. Ultrasound can also check the size of thyroid nodules, and if any nearby lymph nodes have enlarged, it means that the cancer has started spreading.

A radioiodine scan is helpful to determine whether a lump in the neck is cancerous or not. This scan is also ordered for those patients who are already diagnosed with differentiated thyroid cancer to determine if cancer has spread. The patient swallows radioactive iodine, which is absorbed by the thyroid cancer cells, and a camera detects the location and amount of radioactivity. [¹⁷]

Blood Tests

Advanced genomic testing examines the alterations in DNA that can contribute to the growth of cancer. This type of test is usually ordered when an MTC is suspected.

Other lab tests such as thyroid function tests, TSH, T3, and T4 levels in the blood, and levels of protein thyroglobulin are also monitored. [¹⁸]

Symptoms of Thyroid Cancer in Women vs. Symptoms of Thyroid Cancer in Men

Thyroid cancer is three times more common in women as compared to men.

Note that here, we are using the terms “women” and “men” to refer to female and male biological sex at birth, respectively.

The symptoms of thyroid cancer start appearing as changes in skin, nails, and hair, and as women are at a higher risk of developing this cancer, it is better to get checked as soon as any abnormal signs start papering in the body. Symptoms of thyroid cancer in females include:

A lump appears at the base of the neck
Feeling depressed and irritable
Sore throat
Difficulty swallowing
Change in voice
Fatigue

The symptoms of thyroid cancer may produce these symptoms in males;

Sudden hair loss
Low sex drive
Premature ejaculation
Loss of muscle mass

Risk Factors for Thyroid Cancer

The risk factors of thyroid cancer include:

Gender: Thyroid cancer is more common in women.
Age: Women in their 40s and 50s are most susceptible.
Familial medullary thyroid carcinoma: This type of thyroid cancer occurs due to inheriting an abnormal gene.
Radiation: Exposure to radiation, especially in childhood.
Obesity: Obese people are at a higher risk of developing thyroid cancer. [¹⁹]

Thyroid Cancer Prevention

To prevent and lower your risk of developing this disease, it is essential to avoid all risk factors. Avoid unnecessary radiation exposure, such as from imaging tests like X-rays, and CT scans, especially towards children. [²⁰]

Thyroid Cancer Prognosis and Treatment

It is possible to cure most thyroid cancers when they haven’t spread to distant body parts. If cancer cannot be cured, treatment is focused on limiting its growth and removing as much cancer as possible. Other aims of thyroid cancer treatment are to relieve symptoms and prevent cancer from returning.

The Thyroid Cancer Survival Rate

The five-year relative survival rate of thyroid cancer is 98.4%. Almost 2,230 deaths were estimated to have occurred due to thyroid cancer in 2022. [⁴]

Thyroid Cancer Treatment Options

Thyroid cancer is treated through the following treatment options;

Surgery
Radioactive iodine therapy
Thyroid hormone therapy
Chemotherapy
External beam radiation
Targeted drug therapy. [²¹]

Conclusion

Takeaway

If you are someone who is at a higher risk of developing thyroid cancer, you must immediately seek medical advice as soon as you notice any abnormality and symptoms around your neck area. If thyroid cancer is caught at the earliest stage, it is highly curable.