Incidental Thyroid Nodules: A Radiologic Epidemic
cancer, ambulatory/outpatient care, clinical practice patterns/guidelines, racial/ethnic differences in health and health care
Background: The incidence of well-differentiated thyroid cancer has risen dramatically over the last several decades. One proposed explanation for this is the rapid growth in utilization of different radiology studies, which have resulted in large numbers of incidentally identified thyroid nodules. Objectives were to: 1) determine, at our institution, the incidence of incidentally identified thyroid nodules requiring fine needle aspiration; 2) describe the imaging modality and indication for these incidentally identified nodules; and 3) assess the outcomes, including surgical rates, among these nodules.
Methods: A retrospective review was performed of all patients who underwent fine needle aspiration(s) of thyroid nodules between January 2006 and December 2010 by the endocrinology division at a large academic medical center. Medical records were reviewed to identify whether the biopsied thyroid nodule was discovered incidentally through nonthyroid-related imaging or whether it was identified by palpation by patient or physician. Demographic, radiological, surgical and pathological data were assessed.
Results: Fine needle aspirations were performed on 2,296 total thyroid nodules and 1,794 patients; 24% (n = 431) of patients underwent a biopsy for incidentally identified nodules. The most common indications documented for the initial imaging that resulted in an incidental finding of a nodule were neck pain (32.4%), nonthyroid cancer workup (26%) and evaluation for pulmonary embolus (12.8%). Chest computed tomography (CT), magnetic resonance imaging of the spine or neck, and CT of the neck were the most common imaging modalities that led to thyroid incidentalomas (29.2%, 19.9% and 16.1%, respectively). Rates of surgery and identification of cancer did not differ significantly based on the modality or indication for imaging.
Conclusion: In this study, nearly a quarter of patients undergoing fine needle aspiration had their thyroid nodule identified incidentally on imaging. With the continued proliferation of radiology studies, this flood of thyroid nodule incidentalomas is likely to continue to expand.
Chang S. Incidental thyroid nodules: a radiologic epidemic. J Patient Cent Res Rev. 2017;4:147-8.