Mixed echoic thyroid nodules on ultrasound: approach to management.
OBJECTIVE
To evaluate malignancy risk according to ultrasound (US) features and size change on follow-up US in mixed echoic thyroid nodules and to suggest management guidelines thereof.


METHODS
Among patients who underwent US-guided fine needle aspiration biopsy, 316 mixed echoic nodules in 303 patients were included after excluding the patients with pure solid or cystic nodules or without further cytopathologic evaluation. We evaluated malignancy risk according to US features and changes in size and shape on follow-up US.


RESULTS
The malignancy rate was 31.6% (6 of 19) for nodules with suspicious US features and 2.7% (8 of 297) for nodules without suspicious US features (p<0.001). Among 265 nodules with no suspicious US features and initial benign cytology, 15 nodules with suspicious US change and decreased size, 25 nodules with no suspicious US change and increased size, and 225 nodules with no suspicious US change and no change in size were observed on follow-up USs. The malignancy risk thereof was 0%, 0% and 0.4%, respectively (p=1.000).


CONCLUSIONS
Mixed echoic nodules with no suspicious US features and benign cytology can be followed up using US, as they revealed very low malignancy rates, even if they showed growth on follow-up US.
Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea.
Yu-Mee
YM
Sohn
Jung Hyun
JH
Yoon
Hee Jung
HJ
Moon
Eun-Kyung
EK
Kim
Jin Young
JY
Kwak
D000328:Adult; D044963:Biopsy, Fine-Needle / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D014463:Ultrasonography