Computed Tomography Features of Follicular Thyroid Adenoma and Carcinoma

Background: No previous study has investigated the computed tomography (CT) characteristics of follicular thyroid adenoma (FTA) and follicular thyroid carcinoma (FTC). This study aimed to compare the CT features of FTA and FTC. Methods: Eighty-seven consecutive patients with FTA or FTC that underwent preoperative neck CT from January 2006 to December 2013 were included. In each case, single radiologist retrospectively examined the corresponding neck CT under blinded conditions for the histopathological results. The CT features of FTA and FTC were evaluated, as well as the specific CT features for differentiating FTC from FTA. Results: After matching the CT and histopathological results, 55 FTAs and 25 FTCs in 80 patients were analyzed. No statistically significant differences were detected in patient age, gender, nodular size, or location between FTA and FTC patients. The most common CT features in both FTA and FTC included low attenuation, intraglandular configuration, smooth margin, round shape, absence of calcifications, and inhomogeneous enhancement. In particular, the prevalence of decreased, iso-, and increased enhancement was similar in both FTA and FTC. The prevalence of homogeneous attenuation in FTC was higher, whereas the prevalence of inhomogeneous attenuation in FTA was higher. The logistic regression analysis revealed no significant differences between FTA and FTC in any CT features, except for the pattern of attenuation (p = 0.002). Conclusion: No specific CT features of FTA and FTC were identified, and CT may be unhelpful for distinguishing FTC from FTA.