What is an FNA biopsy and why are they important?

An FNA, or fine needle aspiration, biopsy is a common and simple procedure used to sample thyroid nodules.  Thyroid nodules are common, especially if someone in your family has a history of thyroid nodules or thyroid disease.  Nodules cannot be properly evaluated with physical examination and blood tests alone.  The American Thyroid Association recommends FNA biopsy as the procedure of choice for evaluating thyroid nodules and selecting candidates for surgery.  Here at our office, the procedure is done under ultrasound guidance to ensure sample accuracy.  A very fine needle is used to attain a tissue sample from the nodule in question, and samples are sent to pathology for evaluation.  The results are usually back within two weeks.

The pathology results will indicate one of the following findings: benign, non-diagnostic, atypical/suspicious, or malignant.  While the vast majority of thyroid nodules are benign (without cancer), a small percentage do contain thyroid cancer. Nationally, there is a 5% chance the pathologist will not be able to give definite benign or malignant diagnosis, and the report will be non-diagnostic.  Our office non-diagnostic average is only about 2%.  There is also a 1.5-10% national average that the pathologist will read the sample as benign when it is actually malignant, and the report will be a false-negative.  Our office false-negative average is only about 1%.  While very rare and minimal, there are risks involved with the FNA biopsy procedure including infection, bleeding and hoarseness.