Evaluation and Diagnosis of Thyroid Cancer

How is a Thyroid Nodule Evaluated?

A medical history and physical exam performed by Dr. Santillan is important to establish size of gland (goiter) and whether single or multiple thyroid nodules are present.  Also, a complete neck exam is done to evaluate for possible enlarged lymph nodes. Risk factors for thyroid cancer will also be evaluated.

Dr. Santillan will try to determine whether the rest of your thyroid gland is working properly or whether the entire thyroid gland has been affected by a more general condition such as hyperthyroidism or hypothyroidism. This is done by doing thyroid function tests also known as thyroid profile which is a blood test (T4 and TSH).

At the office of Dr. Santillan, specialized tests such as thyroid ultrasound and fine needle aspiration biopsy are performed to further characterize the nodule and its risk of being cancer.  Since most thyroid cancers do not cause symptoms and have normal thyroid function tests, nuclear thyroid scans are no longer considered a first-line method of evaluation. The only time that a nuclear scan is ordered is if there are symptoms and laboratory findings of hyperthyroidism (low TSH).  In these exceptional cases, the nuclear thyroid scan may suggest that no further evaluation or biopsy is needed.  


Thyroid Ultrasound

A thyroid ultrasound needs to be done in all patients who are undergoing work-up for a thyroid nodule. It is a safe and painless non-invasive test done in Dr. Santillan’s office that uses high-frequency sound waves to obtain a detailed image of the thyroid. 

It can give information that is critical to establish risk of cancer by given detailed characteristics such as size, number and type of nodule (solid vs fluid filled). Based on the characteristics of the thyroid nodule Dr. Santillan can estimate risk of cancer and also if biopsy is needed.

Ultrasound features of high-risk nodules:

  • Solid
  • Irregular
  • Microcalcifications
  • High vascular flow
  • Hypoechoic
  • Large size

Ultrasound is also a key component of surveillance for thyroid nodules after initial evaluation is completed. It can be repeated safely during time to establish if nodules are growing or staying the same size. 


Thyroid Fine Needle Aspiration Biopsy (FNA)

Obtaining tissue or sampling cells from the thyroid gland is a very accurate way to determine if the nodule has cancerous cells or give an idea of risk of being malignant. 

Since it only samples cells it cannot determine with complete confidence of cancer is present or not. However, it can predict the risk of malignancy based on the type of cells that are seen under the microscope by an expert cytopathologist.

It is called fine needle aspiration biopsy because it uses a very small needle that even local anesthetic is not necessarily done. This simple procedure is done by Dr. Santillan in his office and patient does not need to be fasting or stop any medications such as blood thinners or NSAIDs pain killers. After biopsy which can take a few minutes patients return to work or home that same day. 

What are the possible results of my FNA biopsy?


Very good news. This means that the thyroid nodule has an extremely low risk of being cancerous (< 3%). These nodules represent the majority of patients. Given benign nature, the majority of these nodules are left alone and observed to monitor growth over time. These nodules will require follow-up ultrasound after several months of initial assessment. Occasionally, Dr. Santillan will remove a benign thyroid nodule because of large size and is causing symptoms of chocking or problems to swallow.

Malignant or suspicious for cancer

The thyroid nodule has been diagnosed as malignant or has a high risk for being cancer up to 75%.  These diagnoses require an expert surgical oncology evaluation by Dr. Santillan and will determine removal of the thyroid gland (partial or complete thyroidectomy) based on size, number of nodules, and risk of lymph node involvement by the cancer. A detailed map of the lymph nodes of the neck will be done at Dr. Santillan’s office to check if cancer has spread to the lymph nodes with potential biopsy of these lymph nodes if found suspicious.

Indeterminate (Atypia, follicular lesion)

In some patients the cytopathologist cannot classify cells as benign or malignant and will give several diagnoses that range from atypia of unknown significance to follicular lesions.  An indeterminate FNA represent a group of patients up to 20% and the majority of these patients do not have a cancer. However, definitive diagnosis can only be made by doing surgery.

Diagnoses in this category will contain cancer rarely (10-30%), so repeat evaluation with FNA over the next months or surgical biopsy to remove half of the thyroid containing the nodule is usually recommended. In these cases, Dr. Santillan will do partial thyroidectomy or close surveillance with repeated ultrasounds/FNA during follow-up months depending on size of the lesion, ultrasound characteristics, molecular testing results and if symptoms are present.  If the surgery confirms a benign nodule, no additional surgery is necessary and most patients do not need thyroid replacement. However, if thyroid cancer is found on the partial thyroidectomy, then completion thyroidectomy is usually recommended to remove all the gland.

There have been new tests to help physicians to make recommendations on patients with indeterminate FNA. These tests instead of looking at the cells of the thyroid nodule will examine the genes (DNA) of the cells and can give a more accurate prediction of malignancy vs benign nature. These are molecular tests done on the samples obtained during the FNA biopsy. Molecular testing can help determine if an indeterminate nodule that is fairly asymptomatic can be observed or removed based on a more accurate risk of malignancy.

Nondiagnostic or inadequate

Rarely after FNA biopsy there are not enough cells for the cytopathologist to give a diagnosis and guide the management of the nodule. Depending on the nodule characteristics by ultrasound and symptoms repeat biopsy or partial thyroidectomy might be necessary. The majority of these nodules are also benign. 


Diagnosis & Treatment of Thyroid Cancer

Thyroid cancer is highly curable and pertains an excellent prognosis. Therefore, any thyroid nodule that is found to contain thyroid cancer, or that is highly suspicious of malignancy, should be removed by an expert thyroid surgeon such as Dr. Santillan.  

As a surgical oncologist and endocrine surgeon who performs more than 100 thyroid surgeries per year in San Antonio, Dr. Santillan is highly experienced with the surgical management of thyroid cancer and will provide you with all the care necessary to the goal of cure.

Prior to surgery Dr. Santillan will do an ultrasound of the neck lymph nodes (lymph node mapping) to assess if lymph node metastases are present in the central compartment and lateral compartments. This information is necessary to plan surgery that is curative and avoid leaving cancer cells behind.

Thyroid nodules that are benign or not cancerous by FNA or that on ultrasound are low risk and no biopsy was performed, it is recommended close surveillance with physical exam and serial ultrasound examination every 6 to 12 months by Dr. Santillan. In some cases, surgical removal of the thyroid nodule could still be recommended even for a nodule that is benign by FNA if it continues to grow, causes symptoms, or has worrisome features on ultrasound over the course of follow up.