Fine Needle Aspiration Biopsy of the Thyroid

You have been found to have one or more nodules in your thyroid, a butterfly shaped gland in the lower area of the neck. These are fairly common and about 95% are benign, not a cancer. To determine which nodules need further treatment, nodules can be biopsied using fine needle aspiration biopsy techniques. The decision to do a biopsy is dependent on size, characteristics of the nodules seen on the ultrasound, and risk factors for thyroid cancer.

The Procedure & Recovery

After adequate anesthesia with a lidocaine injection, an ultrasound is used, and a needle is guided into the nodule. Microscopic amounts of cells are removed, placed onto glass slides, and sent to a pathologist for evaluation. Most nodules are aspirated 5 times.

The risks of the procedure include bleeding, infection, and the possible need to repeat the biopsy. It is normal to experience some mild tenderness or soreness and bruising of the surrounding area. This is comparable to the discomfort after giving blood for a lab test. Ibuprofen (Advil, Motrin), acetaminophen (Tylenol) and ice packs all help with the pain. The puncture sites may bleed a small amount. A band aid or direct pressure can help this.

If there seems to be excessive pain and large swelling in the lower neck after the biopsy, this may indicate deep bleeding in the thyroid. This will have to be evaluated right away. Please call Dr. Wolfe’s office at (206)838-8345. After hours, there are doctors taking call, who can help and provide advice.

After the biopsy, the sample will be evaluated by a pathologist.

Pathologists classify their findings using the Bethesda criteria. These criteria describe the changes in the thyroid cells, the risk of malignancy, and recommendations for further treatment. The following table summarizes the Bethesda system, risk of malignancy for each level, how often we see each level with a biopsy (with Dr. Wolfe’s estimated results) and recommendations for each result.

Bethesda System for Classification of Thyroid Fine Needle Aspiration Biopsies

Bethesda	Description	% of biopsies	% of Risk of malignancy (estimated Wolfe %)	Recommendations
I	Non diagnostic	5-11 % (10)	5-10 %	Repeat biopsy
II	Benign	55-74 % (60)	0-3 %	Observation/surveillance
III	Atypia of undetermined significance	5-15 % (20)	5-15 %	Molecular testing, repeat biopsy, or lobectomy
(also III)	Follicular lesion of undetermined significance		10-30 %	Molecular testing possible removal
IV	Suspicious for follicular neoplasm	2-25 % (10)	10-40 %	Molecular testing possible removal
V	Suspicious for malignancy	1-6 % (3)	45-75 %	Hemithyroidectomy
VI	Malignant	2-5 % (5)	94-99 %	Hemi- or total thyroidectomy

If you have any further questions about your thyroid and plans for evaluation and treatment, please do not hesitate to ask Dr. Wolfe or his staff.

Request an Appointment

Same and next day appointments available