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Diagnosing Thyroid Cancer

  • Fine needle aspiration may be needed to collect a sample that can be biopsied by a pathologist
  • For determining if cancer is present in an abnormally functioning thyroid gland
  • If cancer is detected, surgery is the next step
  • Involves Endocrinology and Surgery


The thyroid gland sits above the collarbone at the base of the neck and makes hormones that are important to keeping bodily functions on track. Approximately 52,000 Americans each year are diagnosed with cancer of the thyroid. Thyroid cancer occurs more often in women than in men and other risk factors include high exposure to radiation and/or certain types of inherited syndromes.

When thyroid cancer is detected early, the five-year survival rate is 99 percent for many kinds of thyroid cancer. This means it's important to have regular physical exams that include getting your thyroid checked so that any necessary treatment can begin quickly. Yale Medicine physicians are highly experienced both in diagnosing thyroid cancers if they are present.

How is thyroid cancer diagnosed?

If a physician notices swelling in the neck or detects one or more lumps in the thyroid during a routine physical—or learns that you have difficulty swallowing, swollen lymph nodes, pain in the throat or neck, or voice changes such as more frequent hoarseness—he or she might want to investigate further. 

That could involve a blood test, to determine whether the thyroid is functioning properly, as well as an ultrasound exam. The doctor may also perform a biopsy, where a needle is used to remove potentially abnormal cells, which then go to a lab for analysis under a microscope. 

What happens during a thyroid biopsy?

The easiest biopsy method for discovering thyroid cancer is called a fine needle aspiration. In this procedure, the doctor injects a thin, hollow needle right into the nodule and removes the suspicious cells, along with some surrounding fluid. Local anesthesia is not usually needed, but the doctor could possibly inject it into the skin that covers the nodule. This type of fine needle aspiration can typically be done in a doctor's office.

“It is a small procedure where a small amount of material is pulled up into the needle, smeared on a slide and sent directly to the pathology lab,” says Manju Prasad, MD, director of head, neck & endocrine pathology at Yale Medicine. “Some of the sample from the needle is also saved for special studies, including molecular testing.”

Typically, this extraction is repeated a few times so that different areas of the nodule can be sampled. “The pathologist uses clear guidelines for thyroid cancer to determine whether it is thyroid cancer or a harmless cyst, and submits the final determination in the form of a pathology report,” Dr. Prasad says.

Often, ultrasound imaging is used during the biopsy to ensure that samples are being taken from the right areas – the most suspicious nodules, if there are more than one. These types of biopsies can also be used to gather samples from swollen lymph nodes, and aid in successfully diagnosing whether the tissue is benign or cancerous.

If there is cancer, the next step may be surgery.

What makes Yale Medicine's approach to diagnosing and treating thyroid cancer unique?

Yale Medicine has a dedicated endocrine surgery section (surgery for glands that produce hormones) within the Department of Surgery for thyroid, parathyroid and adrenal gland surgery, says Dr. Prasad. 

Yale Medicine also offers a lab medicine feature while surgery is in progress. When a surgeon removes one of the four parathyroid glands, tissue is immediately handed over to the lab next to the operating room. The lab then instantly tells the surgeon whether the removal of abnormal glands is complete or whether the surgery should continue. 

"Having the lab adjacent to the operating room [OR] drastically cuts time on the wait for results, time while the patient is on the table in the OR," Dr. Prasad says. "It's important for patients to understand that if there is no interoperative lab up and running, there is a risk the patient could go home and find out later that they are still not cured, and still at high risk and have to have another procedure done."

Yale Medicine is also unique in that it has specialists, and a whole fellowship program accredited by the Accreditation Council for Graduate Medical Education (ACGME), for pathologists with a subspecialty in endocrine, head and neck. Dr. Prasad was instrumental in starting the program and describes the training as "robust."