Sumita L. Adhya MD, Presenter: Nothing to Disclose

Benjamin David Godwin BA, Abstract Co-Author: Nothing to Disclose

Edward G. Grant MD, Abstract Co-Author: Nothing to Disclose

Christopher Lee MD, Abstract Co-Author: Nothing to Disclose

This study was designed to assess the significance of incidental thyroid lesions detected on CT scans by correlating CT findings with sonographic characteristics and fine needle aspiration (FNA) biopsies.

We searched our electronic database for all patients who had received thyroid ultrasounds from 9/2008 through 3/2010, and we identified those patients who had also undergone CT examination of the neck or chest. Thyroid abnormalities were characterized from the CT scans based on size, number, and presence/type of calcifications, and these findings were correlated with sonographic features, as well as FNA biopsy results, when available.

1067 patients received thyroid ultrasounds during the time period, of which 80 patients had also received a CT of the neck or chest. 30 of these patients had pathologic correlation: 1 lesion was malignant (3.3%), 28 lesions were benign (93.3%), and 1 lesion was non-diagnostic (3.3%). Of the 50 patients who did not undergo FNA biopsy, the ultrasound characteristics were deemed to be benign, with no lesion demonstrating increase in size on follow-up ultrasound exams. Of the 78 patients whose lesions were either sonographically or pathologically determined to be benign, CT identified 24 patients (30.8%) with multiple lesions, and 19 patients (24.4%) with coarse and/or rim calcifications. The average longest dimension of the largest lesion measured 1.5 cm.

In our patient population during the time period evaluated, there is a 3.3% prevalence of malignancy among patients with pathologic correlation who received both thyroid ultrasounds and CT. This number may, in fact, be even lower given the benign ultrasound findings among patients without pathologic correlation. Our preliminary data suggests that CT thyroid incidentalomas may potentially be safely ignored if the lesions are less than 1 cm in size, are multiple, or demonstrate coarse and/or rim calcifications. Data spanning a longer time period is currently being collected, and formal statistical analysis is pending.

No guidelines exist for the management of incidental thyroid abnormalities based on their CT appearance. Our research seeks to address this common dilemma using data from our patient population.

Adhya, S, Godwin, B, Grant, E, Lee, C, Incidentally-Detected Thyroid Lesions on CT: Imaging Findings and Significance Using Ultrasound and Pathologic Correlation.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9015487.html