The Value of Sonography in Distinguishing Follicular Thyroid Carcinoma from Adenoma

Abstract

Purpose

Differentiation between follicular thyroid carcinomas (FTCs) and follicular thyroid adenomas (FTAs) is difficult and the sonographic features of FTC are not yet fully established. The purpose of this study is to explore the sonographic features of FTC and the value of sonography in differentiating FTCs from FTAs.

Patients and Methods

A total of 28 pathologically proven FTCs and 53 FTAs in 78 patients who were performed thyroid surgery were included in this retrospective study. The sonographic features of each tumor including an interrupted halo, satellite nodule(s) with or without halo ring, local irregularity of margin and cluster of grapes sign were evaluated. A mode image of FTC halo was built up in our study. The frequencies of the sonographic features were compared by chi-square test or Fisher exact test between FTCs and FTAs. The relative risk of malignancy was assessed by logistic regression analysis.

Results

Logistic regression analysis showed that a thick, irregular and/or interrupted halo with or without satellite nodule(s), hypoechoic or marked hypoechoic echogenicity, a predominantly solid pattern, cluster of grapes sign, micro-or macro-calcifications, rim calcifications correlated with significant increases in relative risk for FTCs (odds ratio 11.48 (1.37–96.56), 6.74 (1.05–43.30), 17.51 (1.78–172.53), 9.55 (1.44–63.46), 9.36 (1.25–70.15) and 17.45 (1.04–292.65), respectively, p<0.05). Two new sonographic features, an interrupted halo and satellite nodule(s) with or without halo ring, can only be found in FTCs.

Conclusion

An interrupted halo and satellite nodule(s) with or without halo ring are specific sonographic features for FTCs. Sonography could play a role in differentiating follicular thyroid carcinoma from adenoma.

Keywords:

• follicular thyroid carcinoma
• follicular thyroid adenoma
• ultrasonography

Acknowledgments

The authors thank all team members and colleagues in the Department of Ultrasound, the First Medical Center, Chinese PLA General Hospital for their helpful cooperation and all the participants for their patience and support.

Abbreviations

FTA, follicular thyroid adenoma; FTC, follicular thyroid carcinoma; PTC, papillary thyroid carcinoma.

Ethics Approval and Informed Consent

This study was approved by Medical Ethics Committee of Chinese PLA General Hospital (S2019-178-02) and the requirement for informed consent was waived because the patients’ data were evaluated retrospectively and anonymously. All members of our team are committed to confidentiality of patients’ data and compliance with the Declaration of Helsinki.

Disclosure

The authors report no conflicts of interest in this work.