Core Needle Biopsy of Thyroid Nodules
A core needle biopsy is a procedure where a small core of tissue is removed from an area of interest with a specially designed needle. The needle takes a piece of tissue about 1-2cm long and about 1mm in diameter. The sample is sent to the pathology laboratory, and the pathologist determines the diagnosis.
A core needle biopsy is similar to a FNA (fine needle aspiration) except that a slightly larger sample is obtained, and the pathologist can usually tell more about the area that has been biopsied (sampled). A core needle biopsy is performed on certain thyroid nodules, usually after the patient has already had an FNA.
A core needle biopsy is recommended for the following thyroid nodules:
- Thyroid nodules where the FNA has been reported as non-diagnostic (Bethesda 1). Note, the non-diagnostic rate with core needle biopsy is considerably lower than with FNA. Core needle biopsy for this indication is approved by multiple thyroid societies worldwide.
- Thyroid nodules where lymphoma, anaplastic thyroid cancer or medullary thyroid carcinoma is suspected. Core needle biopsy for this indication is approved by multiple thyroid societies worldwide.
- Some thyroid nodules where the FNA has been reported as follicular lesion of uncertain significance (Bethesda 3).
- Sometimes when there is a big difference between the FNA result and the ultrasound features.
Dr Hall performs all his core needle biopsies under ultrasound guidance. He uses an ultrasound machine to ensure the needle goes into the area of interest.
Dr Hall will advise you to stop blood thinners (Aspirin, Warfarin, Plavix, Pradaxa, Xarelto) before the procedure. It is best to wear an open shirt so that the whole of the neck is uncovered. The biopsy is done under local anaesthetic in the clinic. You are awake but the area of interest will be numb. First Dr Hall examines the area with an ultrasound. After the lump or nodule is identified, Dr Hall injects some local anaesthetic into the skin. After a few minutes the area will be numb.
The ultrasound machine is used to guide the needle into the lump or nodule. The needle is then activated and you will hear a bang. Usually this is repeated 1-2 times.
A band aid is placed on the injection site. As there is no sedation, it is safe to drive after the biopsy. You can return to work the same day. If you do heavy manual work, take two days off work (the day of the procedure and the following day). This is to prevent any bleeding.
Usually, the pathologist sends a typed signed report to Dr Hall about one to two weeks after the procedure. Occasionally it may take the pathologist longer to issue a report either because of the complexity of your case or because of high workloads. Dr Hall will contact you by phone or text once he receives the pathologist’s report. He will advise you what the next step is to manage your condition.
References:
Na DG, et al. Core needle biopsy of the thyroid: 2016 consensus statement and recommendations from Korean Society of Thyroid Radiology. Korean J Radiol. 2017;18(1):217-237.