Dr. Sheldon Rubenfeld Board Certified in Internal Medicine and in Endocrinology, Diabetes, and Metabolism

What is a Biopsy?d

Ordinarily, when a patient has a thyroid nodule, a thyroid biopsy is performed to decide whether or not surgery is needed. A physician experienced in performing thyroid biopsies will obtain thyroid cells or tissue for analysis by a pathologist, a physician trained to determine whether cells and tissue are normal or abnormal.

A fine needle aspiration biopsy (FNAB) is the most common type of thyroid biopsy. It is called a fine needle aspiration biopsy because the needle is very thin, much thinner than the needle used to draw blood from the arm. The neck may be anesthetized with a local anesthetic, and then a thin biopsy needle, with or without a syringe, is inserted into the thyroid gland. Pain is minimal, and complications are rare. Occasionally, cells cannot be obtained from a solid nodule by a fine needle aspiration biopsy, and a cutting needle biopsy (CNB) is performed. This procedure is essentially the same as the fine needle biopsy, except that a special cutting needle is used. At present, there is no substitute for a needle biopsy in determining, without surgery, whether a nodule is benign or malignant.

After a biopsy specimen is examined in the laboratory, a pathologist may report one of four diagnoses: benign, non-diagnostic (unsatisfactory), malignant, or suspicious.

When selecting a pathologist, the referring physician must carefully consider the pathologist’s experience in interpreting thyroid biopsies. One of the main functions of a physician is to ensure that the pathologist with whom he works is of the highest quality.