What Does a Hypoechoic Nodule on My Thyroid Mean?
Hypoechoic means “below or beneath” and echoetic means “to emit sounds”. A hypoechoic nodule is one that emits noxious substances (such as carbon monoxide) from its surface. These are called hypoxic nodules. They are found in the body’s tissues such as blood vessels, nerves, organs and other soft tissue. When these nodules get big enough they cause damage to vital organs like the heart and brain.
A hypoechoic nodule on your thyroid gland may mean that it is leaking toxins into your bloodstream. If you have a large number of them then you could develop symptoms similar to those associated with cancer. The main source of these toxins is food. But if there are too many of them, then they can leak out through your skin and enter your blood stream.
The most common type of hypoechoic nodule is called a thyrotropin releasing hormone receptor (TRH) positive hyperplasia (T4 PR). T4 PR refers to the fact that the thyroid produces this hormone. TRH stands for triiodothyronine receptor.
When a person consumes food, the stomach breaks it down into tiny little bits. These bits are called molecules. Your body cannot use the nutrients (vitamins and minerals) in these molecules directly. Instead, they must undergo a process which involves wrapping them inside a protein coating.
This process is called “bioavailability”.
Some of these nutrients are used to build new body tissue such as hair and skin. Some of the others are used to create hormones and neurotransmitters. If a person consumes too much of a certain type of nutrient, it may build up in the body and cause disease. This is what happens with hypoechoic nodules.
If too much builds up in your blood then you may experience symptoms such as those listed below.
Thyroid Gland Nodules
A nodule is a small lumps. They can appear on any part of your body such as the skin (moles), joints, organs and muscles. Nodules are small, round and hard to the touch. They can either be solid or soft.
The main types of nodules that have been found on the thyroid are described below:
Painless Thyroid Nodule
This is the most common type of thyroid nodule. It is usually painless and found during an ultrasound scan of the thyroid gland. Most painless nodules are non-cancerous (benign). Physicians used to think that even benign nodules could produce a lot of hormones.
However, this has been shown to be untrue in most cases.
Painful Thyroid Nodule
This type of nodule is rare. It is usually solid and stiff to the touch. If you have a painful nodule then you probably will experience pain in your chest and neck. The pain is caused by the pressure the nodule exerts on your nerves.
This type of nodule is more likely to be cancerous than a painless nodule.
Giant Thyroid Nodule
As the name suggests, this nodule is very large. There are two types of giant nodules: those under 4 cm and those over 4 cm in diameter. The over 4 cm tumors are more likely to become cancerous. The smaller ones usually do not develop into cancer.
These nodules are usually solid and firm to the touch.
Merkel Cell Carcinoma
This type of nodule is rare and can form in the thyroid gland or on the skin. Despite its name, this type of cancer does not start in cells called Merkel cells. Instead, it starts in the skin. This tumor develops from cells that turn into cancer (dubbed carcinoma).
Carcinomas can also form in the skin, nerves, sweat glands, blood vessels and hair follicles. As such, it is not a specific subtype of cancer.
Trabecular Carcinoma
This type of thyroid cancer starts in the spaces within thyroid tissue (known as the trabecular). It is a hard, round nodule that can feel firm to the touch. It usually grows slowly and rarely spreads to other parts of the body. Most people with this type of cancer do not experience any symptoms.
If the cancer does spread, then it usually goes to the lungs.
Follicular Carcinoma
This type of thyroid cancer starts in the follicles (the spaces that produce thyroid hormones). Most of the time, this tumor does not produce any hormones. Advanced tumors can grow and invade other tissues in the body. This invasion causes symptoms.
If invasion is small, the person may not experience any symptoms at all.
Anaplastic Carcinoma
This rare and aggressive cancer starts in cells that line the thyroid gland. It is more common in the elderly but can affect people of all ages. It grows quickly and has spread to the lymph nodes and other areas of the body before a person notices symptoms. These tumors very rarely produce thyroid hormones.
Medullary Carcinoma
This type of thyroid cancer is also rare. It starts in cells known as the medulla. This tumor can develop in different ways. It may start from thyroid stem cells, C-cells that migrate from the brain or remnants of fetal thyroid tissue.
This type of cancer is more common in young adults.
Papillary Carcinoma
This type of thyroid cancer starts in the follicles (known as the papilla). The exact cause is unknown. It is more common in older adults and rarely spreads to other parts of the body. If it does spread, the most common location is to the lungs.
Waldenstrom Macroglobulinemia
This type of cancer starts in B-cells (a type of white blood cells). It results from an abnormal increase in a type of white blood cell called a gamma globulin called macroglobulins. As such, this cancer is marked by high levels of a type of protein called immunoglobulins. It is more common in older males.
Pleomorphic Salivary Gland Tumor
This rare type of tumor forms in the parotid salivary duct. It is most likely a type of salivary gland cancer instead of a thyroid cancer. Most of the time, this type of tumor does not invade other parts of the body. The exact cause is unknown but there are certain factors that increase the risk of developing it.
Lymphoepithelioma
This rare type of salivary gland cancer starts in cells that normally line salivary glands, called epithelial cells. It is marked by the abnormal clumping of a type of white blood cells called lymphocytes. Most of the time, it grows slowly and does not spread to other parts of the body. However, it can rarely spread to the lungs or other parts of the body.
What are the Risk Factors of Developing Different Types of Thyroid Cancers?
The type of risk factors depend on the type of thyroid cancer. Specific types of thyroid cancers have their own risk factors. Some of the factors which can increase your risk of developing a certain type of thyroid cancer are:
Papillary Carcinoma
Some studies suggest that people with type 1 diabetes may have a slightly higher risk of developing papillary cancer.
Follicular Carcinoma
Some studies suggest that exposure to asbestos and cigarette smoke may increase the risk of developing follicular cancer.
Anaplastic Carcinoma
This rare type of thyroid cancer is more common in older adults. Some studies suggest that people over the age of 50 who have had radiotherapy to the head, neck or chest are at an increased risk of this cancer.
Medullary Carcinoma
Some studies suggest that there may be a genetic link to this type of cancer. It tends to run in families. A specific gene referred to as the multiple endocrine neoplasia (MEN) gene syndrome is strongly linked with medullary carcinoma. This syndrome also increases the risk of developing other endocrine tumors such as parathyroid tumors, pancreatic tumors and pituitary tumors.
Papillary Thyroid Carcinoma
Some studies suggest that people with type 2 diabetes may have a slightly higher risk of developing this cancer.
Follicular Thyroid Carcinoma
There are certain factors that can increase the risk of developing this cancer. These factors are:
Exposure to certain types of radiation and chemicals
Having an inherited syndrome called multiple endocrine neoplasia (MEN) type 2 or CHARGE syndrome
Having an inherited condition known as familial adenomatous polyposis (FAP)
Having another type of cancer such as leukemia or skin cancer
Treatment for other types of cancer with radiotherapy and/or chemotherapy
Papillary Thyroid Carcinoma
This cancer is more common in females.
Medullary Thyroid Carcinoma
This cancer is more common in younger adults.
Follicular Thyroid Carcinoma
The risk of this cancer increases with age. Having an inherited syndrome called multiple endocrine neoplasia (MEN) type 2 or CHARGE syndrome also increases the risk of developing this cancer.
Treatment for Different Types of Thyroid Cancers
Your doctor can analyze the cells of your thyroid cancer and determine the exact type in order to decide the best treatment for you. The treatment options include surgery, radiation therapy and chemotherapy. Your surgeon will take out all or part of your thyroid and may also take out some of the surrounding lymph nodes as well. If the cancer has spread to these nodes, they will be analyzed to see if they contain any cancer cells.
Surgery is the main treatment for most types of thyroid cancer. The surgeon may take out all or just part of your thyroid gland. If they take out part of your thyroid, they will take out all of the cancer and some surrounding healthy tissue to make sure there are no more cancer cells present. This is known as a partial thyroidectomy.
If the cancer has spread to other areas of your body, your surgeon may take out more than just your thyroid gland and may perform a total thyroidectomy. The surgeon will also remove some of the lymph nodes in your neck. These nodes will be analyzed to see if they contain any cancer cells. This surgery is complex and in some cases the surgeon may decide to take out an entire lobe of your liver or part of your pancreas instead of your entire thyroid gland.
Your surgeon may also take out some of your neck tissue. If this is the case, you will have a skin graft after your surgery in order to cover your neck.
If you are diagnosed with anaplastic thyroid cancer or medullary thyroid cancer, you may undergo chemotherapy before having surgery to try to shrink the size of your tumors. The type of chemo drug used will be determined by your doctor based on your specific situation.
If you are diagnosed with the other types of thyroid cancer, your doctor may treat you with external beam radiation to the neck and head after surgery. This is known as post-surgical radiotherapy or adjuvant radiotherapy.
External beam radiation is a common treatment for many different types of cancer and is used to destroy any remaining cancer cells after surgery. Your doctor will aim high energy rays directly at the surgical site in an attempt to destroy any remaining cancer cells. The rays can also travel beyond the surgical site and damage other organs in the area.
External beam radiation can cause nausea, fatigue, baldness, skin burns and mouth sores.
If you are diagnosed with papillary or follicular thyroid cancer, your doctor may suggest monitoring the tumor(s) rather than immediately treating them with surgery or other therapies. This is because these types of cancer tend to grow very slowly. You and your doctor will re-examine the tumor(s) every few months and determine whether treatment is necessary or not.
Different types of thyroid cancer are treated in different ways based on the exact type of cancer, the extent of the disease and your medical history. As with any cancer, early detection is key. If you notice any symptoms of thyroid cancer, make an appointment to see your doctor right away. Early detection and treatment increase your chances of survival.
Sources & references used in this article:
Interobserver agreement in assessing the sonographic and elastographic features of malignant thyroid nodules by SH Park, SJ Kim, EK Kim, MJ Kim… – American Journal of …, 2009 – Am Roentgen Ray Soc
The diagnostic efficiency of ultrasound in characterization for thyroid nodules: how many criteria are required to predict malignancy? by A Ozel, SM Erturk, A Ercan, B Yılmaz… – Medical …, 2012 – medultrason.ro
Thyroid ultrasound reporting lexicon: white paper of the ACR thyroid imaging, reporting and data system (TIRADS) committee by EG Grant, FN Tessler, JK Hoang, JE Langer… – … the American college of …, 2015 – Elsevier
