Introduction:
A biopsy is a procedure that involves removing cells or tissues from the location of a disease for laboratory evaluation in order to detect the existence or extent of the disease. A thyroid biopsy is often done to examine a thyroid nodule that may be functional or nonfunctional. A thyroid biopsy determines whether these nodules are cancerous or non-cancerous. Thyroid biopsies are basically of four types, and generally, it is a very non-invasive and safe procedure with very little scope for complications. A thyroid biopsy is usually done by a surgeon.
What Is Thyroid Gland?
The thyroid gland is a small butterfly-shaped endocrine gland. It is present in front of the neck and typically consists of two lobes connected by a bridge of tissues known as the isthmus. Both of these lobes are present on either side of the windpipe. The thyroid gland is a vital gland responsible for several crucial functions of the body. The primary function of the thyroid is to produce thyroid hormones (thyroxine, triiodothyronine, and calcitonin). These hormones are essential for the growth, development, and regulation of the body's metabolism. A thyroid problem can cause multiple systemic problems like hyperthyroidism, hypothyroidism, goiter, Graves’ disease, Hashimoto’s disease, thyroid nodules, etc.
What Is a Thyroid Nodule?
Thyroid nodules are small lumps present in the thyroid gland. These lumps may be solid or fluid-filled. Although these nodules are primarily asymptomatic, sometimes they may be pressed on the windpipe and food pipe and cause difficulty swallowing or shortness of breath. These thyroid nodules either do not affect thyroid function, or they can cause hyperthyroidism. In rare cases, these nodules can become cancerous. The cornerstone of thyroid nodules or thyroid cancer is surgery. The surgery involves partial or complete removal of the thyroid gland. Thyroid nodules are diagnosed with the help of a thyroid scan and thyroid biopsy.
What Is Thyroid Biopsy?
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Thyroid biopsy is a diagnostic procedure done to evaluate thyroid nodules and determine whether these nodules are cancerous or non-cancerous. Thyroid nodules and tissues are easily accessible through a needle; therefore, there is no need to undergo an invasive procedure to get a sample tissue from the thyroid. Instead, a very fine needle is inserted inside the thyroid, and a small sample of tissue is extracted from the nodule for evaluation. This type of biopsy is called fine-needle aspiration biopsy.
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The needle is then inserted multiple times at several sites of the nodule or goiter to collect cells.
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These cells are then stained and studied under a microscope.
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The nodule is then classified as non-diagnostic, benign, suspicious, or malignant based on the microscopic evaluation.
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Often this biopsy is done with the help of ultrasound, and it is known as ultrasound-guided fine-needle aspiration biopsy. This procedure uses sound waves to help locate a nodule or abnormality in the thyroid gland.
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This process is less invasive than surgical biopsy and leaves little to no scarring.
What Are the Types of Thyroid Biopsy?
Fine-needle aspiration biopsy is the most commonly used procedure in thyroid biopsy. However, there are times when doctors perform another type of thyroid biopsy. Different types of thyroid biopsy are mentioned below:
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Fine-Needle Aspiration Biopsy: In this method, a small needle is inserted into the thyroid, and a sample of tissue is collected. This method is often performed with ultrasound imaging. The needle is inserted through the skin under direct imaging guidance.
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Core Needle Biopsy: This method is just like fine-needle aspiration biopsy but with a bigger needle. Core needle biopsy is used as a backup plan if fine-needle aspiration does not give a precise result.
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Surgical Biopsy: This method is rarely used because it is invasive. In this method, an opening is made in the neck to remove the nodule surgically.
When Is a Thyroid Biopsy Done?
A thyroid biopsy is generally done for the following reasons:
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To determine if a thyroid nodule is benign (non-cancerous) or malignant (cancerous).
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To find out the cause of goiter or nodule.
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In cases of nodules bigger than one centimeter, especially if the imaging tests show it is solid and has calcium.
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When the nodule does not have a clear margin around it.
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In the case of a thyroid nodule that is growing rapidly.
How Is a Thyroid Biopsy Done?
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A thyroid biopsy is done by cleansing the insertion area with an antiseptic followed by numbing the area with medication or local anesthesia.
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Next, a small amount of water-soluble gel is applied over the thyroid nodule. A fine needle is then inserted through the skin under ultrasound imaging guidance, and samples of cells are aspirated from the thyroid nodule or goiter. This step is repeated several times at different nodule sites, and samples are collected.
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After a sufficient number of tissues is collected, the needle is removed. Once the hand is removed, pressure is applied to the area to decrease the risk of bleeding from the site.
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No sutures are needed. However, a bandage may be placed at the site. The whole procedure is generally completed in thirty minutes.
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After the process is completed, the samples are sent to the laboratory and evaluated.
What Are the Risks for Thyroid Biopsy?
Thyroid biopsy is an effortless and non-invasive procedure. However, there might be a few risks associated with it:
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Bleeding at the site of biopsy.
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Infection.
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Damage to structures surrounding the thyroid gland.
What Happens After Thyroid Biopsy?
The biopsy site may be sore for a few days, and there might be some pain that can be managed by taking over-the-counter painkillers like Acetaminophen. However, most people will be able to resume their everyday life and work right away.
What Are the Results of Thyroid Biopsy?
It may take several days to get the results of a thyroid biopsy. If the biopsy confirms the nodule to be cancerous, surgery is advised. However, if the nodule is non-cancerous, the doctor may recommend waiting and observing the nodule with regular follow-ups to see any suspicious changes. In addition, thyroid hormone pills may be advised to arrest the growth of thyroid nodules.
Conclusion:
Thyroid biopsy is a simple and minimally invasive diagnostic procedure to evaluate a thyroid nodule or other thyroid abnormalities. The test is safe and has few risks when performed by a skilled practitioner. A thyroid biopsy is done with a fine-needle aspiration guided by ultrasound imaging. The test is mainly used to determine whether a thyroid nodule is cancerous or non-cancerous.
