Definition – What is a thyroid biopsy?
A thyroid biopsy is a removal of thyroid tissue for microscopic examination. The tissue samples can be examined for possible cancer cells, inflammatory cells or antibodies and help in the diagnosis of thyroid diseases. In the case of malignant thyroid diseases, they are the means of choice for ensuring the diagnosis. It is also known as fine needle biopsy.
Indication for thyroid biopsy
Thyroid biopsy is mainly used in the diagnosis of tumors. As a rule, patients have had an ultrasound examination beforehand, which has shown unclear or tumor suspicious findings. If the findings in the thyroid gland are unclear, such as lumps in the tissue, tissue samples are taken and histologically examined.
As a rule, a cold lump of 1.5 cm or more is considered suspicious in the ultrasound examination. Cold means that the node shows no activity. Antibody-producing nodules are accordingly described as hot. Micro calcification in the thyroid gland, which can also be detected by ultrasound, is also considered suspicious and is a further indication for a biopsy.
Preparation before thyroid biopsy
A thyroid biopsy should usually be preceded by a detailed medical history and physical examination. There should be a definitive indication for the biopsy. If the doctor feels a hard, non-displaceable lump in the patient, an ultrasound examination is usually performed to better assess the lump.
If the nodules are cold, low-echo nodules of more than 1.5 cm in diameter, the indication for a biopsy is given. In addition, blood is taken from the patient. This is done to differentiate between hard and soft nodules.
The thyroid gland values (TSH, T3, T4) are examined. If the indication for a biopsy is given, the patient is first informed intensively by a physician about the upcoming procedure. The patient has to give his signature for consent.
How does the thyroid biopsy work?
A thyroid biopsy, or fine needle biopsy, is a small examination with few complications. It does not require an inpatient stay or anesthesia. It is usually performed on an outpatient basis.
Once the patient has been informed, the skin area around the thyroid gland is disinfected to prevent infection. The ultrasound machine is then used to find a suitable site for taking a biopsy. Care is taken to ensure that there are no large blood vessels in the way and that there is enough thyroid tissue.
Once a suitable site has been found, a puncture needle is inserted into the skin up to the thyroid gland under ultrasound control. Using negative pressure in the syringe, some tissue is then removed. This is then placed on a microscope slide.
Afterwards another tissue removal is performed. Afterwards the small wound is treated. The examination is hardly painful, similar to taking a blood sample. The tissue samples are now sent to the laboratory and examined by a pathologist.