Diagnosis of Thyroid nodules


In addition to biopsy of a nodule to to rule out the possibility of cancer, tests are also conducted to know if your thyroid is functioning properly.

March 7, 2018

Diagnosis of Thyroid nodules

Thyroid nodules are solid or fluid-filled lumps which are formed within or on your thyroid gland that is at the base of your neck, below the voicebox (larynx) and above the collarbones.

Diagnosis of Thyroid nodules:

In addition to biopsy of a nodule to to rule out the possibility of cancer, tests are also conducted to know if your thyroid is functioning properly. The different type of tests include:

Physical examination:

As a nodule in your thyroid gland will usually move up and down during swallowing, you will be asked to swallow while your doctor examines your thyroid. Signs and symptoms of hyperthyroidism, such as tremor, overly active reflexes, and a rapid or irregular heartbeat will be looked by your doctor. Other sign and symptoms such as a slow heartbeat, dry skin and facial swelling can also be checked which will indicate hypothyroidism.

Thyroid function tests:

This test help determine if the thyroid gland is functioning normally. Thyroid function tests are a series of blood tests which include T3, T4, and TSH and are done to determine how well your thyroid gland is working. Thyroid is a small butterfly shaped gland that is located in the lower-front part of your neck that typically produces three hormones namely triiodothyronine (T3), thyroxine (T4), and calcitonin. The thyroid produces hormones when the pituitary gland releases TSH in the blood. Thyroid-stimulating hormone or TSH is responsible for regulation of metabolism, release of hormones by the thyroid gland, energy generation, and mood. A TSH blood test to check for the existence of any underlying causes of a typical production of hormones in these two glands. If the TSH level comes abnormal, then further screening for overactive or underactive thyroid gland is done.

Ultrasonography:

This imaging technique uses high-frequency sound waves to create detailed images of the thyroid. It provides the best information about the shape and structure of nodules. This test is also used to distinguishes thyroid cysts from solid nodules or to determine if multiple nodules are present. It may also be used as a guide in performing a fine-needle aspiration biopsy.
Ultrasound guidance enables physicians to biopsy the nodule to obtain an adequate amount of sample for interpretation. The size of the nodule should be monitored, even if it is not reported as cancerous. A nodule with a benign biopsy that is stable or decreasing in size does not require surgical treatment unless it is causing any bothersome symptoms.

Fine-needle aspiration (FNA) biopsy:

In this procedure a long, thin needle through your skin and into the thyroid nodule is inserted. Typically ultrasound imaging is used to precisely guide the needle into the nodule. Your doctor uses the needle to remove a sample of cells. The sample is analyzed in the laboratory to look for cancer cells. Looking in to the sample the pathologist will then decide if the nodule is benign or malignant. The procedure is carried out in your doctor's office which takes about 20 minutes and patients can usually return to work or home afterward with no ill effects.

Thyroid scan:

A thyroid scan is a picture of the thyroid gland taken after an isotope of radioactive iodine is injected into a vein in your arm. A special camera produces an image of your thyroid on a computer screen while you lie on a table.
As hot nodules take up more of the isotope than normal thyroid tissue does, will be clearly visible on the scan. These nodules that produce excess thyroid hormone nodule causes hyperthyroidism and can be treated with radioiodine or surgery.
Cold nodules are nonfunctioning and appear as defects or holes in the scan. Cold nodules are almost always noncancerous, but a few cold nodules are cancerous. A thyroid scan can not distinguish between benign and malignant cold nodules, which is a big disadvantage of this procedure.
Depending on how long the isotope reach your thyroid gland, the time taken for a thyroid scan varies. As your neck is stretched back, and you will be exposed to a small amount of radiation, you may have some neck discomfort during the scan. For a pregnant woman, neither a thyroid scan nor radioiodine treatment is advisable. Breast-feeding is not allowed for women undergoing radioiodine treatment as a small amounts of radioactive iodine will be excreted in breast milk which could permanently damage the thyroid of the infant.