Analysis of the Malignancy Rate for Thyroid Nodules based on the Use of a Fine Needle Aspiration Biopsy and Ultrasonography.
- Author:
Ju Wan CHOI
1
;
Ji Won PARK
;
Han Young JEONG
;
Hye Jung KIM
;
Gab Chul KIM
;
Yong Sun KIM
;
Ji Young PARK
;
Hui Joong LEE
Author Information
1. Department of Radiology, Kyungpook National University Hospital, Daegu, Korea. knuhrad@yahoo.co.kr
- Publication Type:Original Article
- Keywords:
Thyroid nodule;
Fine needle aspiration biopsy;
Thyroid US
- MeSH:
Biopsy;
Biopsy, Fine-Needle;
Cohort Studies;
Female;
Follow-Up Studies;
Humans;
Sensitivity and Specificity;
Thyroid Gland;
Thyroid Nodule
- From:Journal of the Korean Society of Medical Ultrasound
2008;27(4):213-219
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: This study was designed to analyze the malignancy rate for thyroid nodules determined after a fine needle aspiration biopsy (FNAB) and ultrasonography (US) and to propose follow-up FNAB indications. MATERIALS AND METHODS: A total of 287 patients (265 female, 22 male) who underwent repeated US-guided FNABs were included in the cohort study. The results of the FNABs were classified as inadequate, benign, indeterminate, suspicious for a malignancy and a malignancy. The US findings were assigned five grades according to the possibility of a malignancy present. The frequency of a malignant nodule was evaluated by the use of the Kaplan-Meier method and Cox proportional risk model. RESULTS: The malignancy rates of inadequate, benign, and indeterminate nodules were 12.8%, 8.2% and 37.5%, respectively, for the FNAB findings. The rates of grades 3, 4 and 5 were 38.6%, 50.0% and 53.8%, respectively, for the US findings. Inadequate and indeterminate nodules as determined by an FNAB and grades 3, 4 and 5 assigned after US showed a higher malignancy rate than other nodules and would be regarded as high risk lesions. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 93.3%, 38.4%, 22.0%, 96.9% and 47.0%, respectively, if the nodule was considered a high-risk lesion, based on the FNAB or US findings. CONCLUSION: Thyroid nodules should be evaluated based on an FNAB and US findings. If a thyroid nodule is classified as a high-risk lesion, a follow-up study is needed due to the high malignancy rate.
