What to Do With Incidental Thyroid Nodules on Imaging? An Approach for the Radiologist
Section snippets
What Is the Problem With Thyroid Incidentalomas?
The first step in making a decision about further workup is to understand clinical perspectives about thyroid nodules and the impact of investigating nodules. There are 3 facts the radiologist must appreciate.
Ultrasound
Of all the imaging modalities, high-resolution ultrasound provides the best modality for evaluating size and morphology of thyroid nodules, and it is the preferred modality for further characterization of nodules. The Society of Radiologists in Ultrasound (SRUS) and the American Thyroid Association (ATA) independently established recommendations of sonographic criteria for FNA (Table 1).16, 17 The ATA recommends FNA for suspicious sonographic features, such as microcalcification,
An Approach to Reporting Nodules and Workup
The radiologist has a role in detecting incidental thyroid nodules and making recommendations to steer the clinician's decision about workup when appropriate. When an incidental nodule is detected on ultrasound, we consider both SRUS and ATA guidelines in forming our approach. Currently, we recommend further workup with FNA if a solid nodule is >1 cm in diameter with any of the following suspicious sonographic features: microcalcifications, hypoechoic composition, increased vascularity,
Conclusions
When faced with an incidental thyroid nodule on imaging, the radiologist's dilemma is to weigh the possibility of thyroid malignancy with the cost of recommending workup. To develop a strategy of dealing with these incidentalomas, radiologists should understand the clinical background behind thyroid nodules and malignancy, and the limitations of imaging in distinguishing thyroid malignancy from benign nodules. We offer our approach to report incidental thyroid nodules based on risk categories.
References (33)
- et al.
Risk of malignancy in thyroid incidentalomas identified by fluorodeoxyglucose-positron emission tomography
Surgery
(2001) - et al.
Gross and microscopic findings in clinically normal thyroid glands
J Clin Endocrinol Metab
(1955) - et al.
Thyroid gland: US screening in a random adult population
Radiology
(1991) - et al.
Incidentally discovered thyroid nodules: Incidence, and grayscale and colour Doppler pattern in an adult population screened by real-time compound spatial sonography
Radiol Med
(2006) - et al.
Importance of thyroid abnormalities detected at US screening: A 5-year follow-up
Radiology
(2000) - et al.
Thyroid incidentalomas: Management approaches to nonpalpable nodules discovered incidentally on thyroid imaging
Ann Intern Med
(1997) - et al.
Ultrasonography-guided fine-needle aspiration of thyroid incidentaloma: Correlation with pathological findings
Clin Endocrinol (Oxf)
(2004) - et al.
The prevalence and significance of incidental thyroid nodules identified on computed tomography
J Comput Assist Tomogr
(2008) - et al.
Clinical and economic impact of incidental thyroid lesions found with CT and MR
Am J Neuroradiol
(1997) - et al.
Systematic review: Prevalence of malignant incidental thyroid nodules identified on fluorine-18 fluorodeoxyglucose positron emission tomography
Nucl Med Commun
(2009)