By MATTHEW SHLAPACK, MD
Mrs. Smith undergoes a routine carotid artery doppler study as part of her evaluation following a recent CVA. While she is pleased to hear that no significant blockage or stenosis was present, the technologist remarks that Mrs. Smith does have a distinct thyroid nodule present in her right thyroid lobe. What should be done next?
Thyroid nodules are being diagnosed with increasing frequency. Studies estimate that between 1:3 and 1:2 adults have a thyroid nodule. While experts disagree if all the increase in diagnosis is secondary to more imaging studies being performed, most do agree that a large part of this rise is being driven by increased imaging. While thyroid nodules are common, it is essential that when found, they are evaluated.
The workup of thyroid nodules is aimed at answering two questions. Are the nodule or nodules hot nodules, producing excess thyroid hormone? Do the thyroid nodules contain thyroid cancer?
Hot nodules are variably described as toxic nodules or hyperfunctioning nodules. While exceptions can occur, as a rule, hot nodules are not malignant. With this in mind, determination, if thyroid nodules are hot, should typically be done first. This can usually be accomplished by a simple measurement of TSH. If the TSH is within normal limits, the nodule or nodules are most likely not hot and sending the patient for a thyroid uptake and scan is usually not necessary. If the TSH does return suppressed, then further evaluation to confirm hyperfunctioning should be considered.
Once it has been confirmed that a patient’s thyroid nodules are not hot, the focus shifts to an assessment of possible malignancy. Unfortunately, this question can only be answered by performing a biopsy and obtaining tissue.
The good news is that not every thyroid nodule requires a biopsy. We now have excellent research regarding the likelihood of a nodule being malignant. This has resulted in a specific set of guidelines that aid us in deciding which patients should and should not be referred for biopsies.
These guidelines focus on three main groups of information. The first set of information regards reported symptoms and patient-specific risk factors for thyroid cancer such as a history of exposure to radiation or a family history of thyroid cancer. The second set relates to specific exam findings such as associated lymphadenopathy and immobility of the nodule itself. Finally, the ultrasound appearance of the nodules plays an essential role in determining if a biopsy is appropriate.
Returning to our patient. Mrs. Smith was found to have a normal TSH. She does not have risk factors for thyroid cancer or concerning exam features; however, her right-sided thyroid nodule did meet the criteria for biopsy based on the appearance of ultrasound. She underwent an ultrasound-guided fine needle biopsy. She returns to your office and is frustrated to hear that the pathology returned indeterminate. What is the next step?
Thyroid nodule biopsy results can be broadly divided into four main categories: benign, malignant, insufficient specimen, and indeterminate pathology. Patients are understandably frustrated to go thru a procedure such as a biopsy only to hear that the question of malignancy remains unanswered.
The good news is that proceeding with a repeat biopsy or empiric thyroidectomy is no longer always required. We are now fortunate to have additional evaluation tools at our disposal. There are several, well-validated, genomic tests that can be run on thyroid aspirates or even the pathology slides themselves. Often, the results of this additional testing will clarify if an indeterminate result is benign or malignant.
Mrs. Smith’s thyroid nodule aspirate was sent for additional testing and she was relieved to hear that her thyroid nodule is benign. She will benefit from a repeat ultrasound in the future to document stability, but at this time, no further workup or treatment is required.
Providers will continue to be confronted with thyroid nodules being found incidentally during imaging exams. We must remain cognizant of how distressing these findings can be to our patients. As in all areas of medicine, our patients are exposed to a steady barrage of information from questionable sources, now more than ever.
Referral to an Endocrinologist with experience in the evaluation of thyroid nodules can often lead to definitive answers within a few appointments. This specialist can also oversee any needed surveillance, which often can be done with as little frequency as an annual follow-up.
As the trend of increased imaging continues, there is no doubt that incidental findings will continue to confront us. The great news is that the advances that have been made in the area of thyroid nodules have provided us with the tools to adequately evaluate them, both for our patients’ safety and their peace of mind!
Matthew Shlapack, MD, is a Board-Certified Endocrinologist practicing at Orlando Endocrinology with a mission to ensure that patients benefit from all the latest advances in medicine, helping to preserve their health and maintain their independence. Shlapack completed both his Internal Medicine Residency and his Endocrinology Fellowship at The University of South Carolina, School of Medicine, and was awarded his Doctor of Medicine degree from Ross University Medical School. He graduated from The University of Maryland, College Park with bachelor’s degrees in both Neurobiology, Physiology, as well as Psychology. He attended Ross University Medical School. Visit http://orlandoendocrinology.com