title: Sonographic features of thyroid nodules that may help distinguish clinically atypical subacute thyroiditis from thyroid malignancy.
abstract: OBJECTIVE
  The purpose of this study was to evaluate sonographic features for distinguishing clinically atypical subacute thyroiditis from malignant thyroid nodules.
  
  
  METHODS
  A total of 165 hypoechoic thyroid nodules without calcification in 135 patients with histologic diagnosis were included in this study. These nodules were classified into 2 groups: a thyroiditis group (55 nodules in 36 patients) and a malignancy group (110 nodules in 99 patients). The sonographic features of the groups were retrospectively reviewed.
  
  
  RESULTS
  No significant differences were detected for the variables of marked echogenicity, a taller-than-wide shape, and mixed vascularity. However, a poorly defined margin was detected more frequently in the thyroiditis group than the malignancy group (P < .05); it yielded a high capability for differential diagnosis of atypical subacute thyroiditis, with sensitivity and specificity of 87.3% and 80.9%, respectively. Centripetal reduction echogenicity was observed exclusively in the thyroiditis group, with high specificity (100%) but low sensitivity (21.8%) for atypical subacute thyroiditis diagnosis. All of the thyroiditis nodules with a positive color signal showed noninternal vascularity (negative predictive value, 100%).
  
  
  CONCLUSIONS
  There is a considerable overlap between the sonographic features of atypical subacute thyroiditis and thyroid malignancy. However, the margin, echogenicity, and vascularity type are helpful indicators for differential diagnosis of atypical subacute thyroiditis.
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Fu-shun
authors: FS
authors: Pan
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Wei
authors: W
authors: Wang
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Yan
authors: Y
authors: Wang
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Ming
authors: M
authors: Xu
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Jin-yu
authors: JY
authors: Liang
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Yan-ling
authors: YL
authors: Zheng
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. xxy1992sys@163.com.
authors: Xiao-yan
authors: XY
authors: Xie
authors: Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound (F.P., W.W., Y.W., M.X., J.L., Y.Z., X.X.), and Department of Vascular and Thyroid Surgery (X.L.), First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors: Xiao-xi
authors: XX
authors: Li
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D013968:Thyroiditis, Subacute / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult
keywords: carcinoma; head and neck ultrasound; sonography; subacute thyroiditis