title: Conventional ultrasonography and real time ultrasound elastography in the differential diagnosis of degenerating cystic thyroid nodules mimicking malignancy and papillary thyroid carcinomas.
abstract: BACKGROUND
  To evaluate the diagnostic utility of conventional ultrasonography and real time ultrasound elastography in differentiating degenerating cystic thyroid nodules mimicking malignancy from papillary thyroid carcinoma.
  
  
  METHODS
  We retrospectively analyzed conventional ultrasonographic and elastographic characteristics of 19 degenerating cystic thyroid nodules mimicking malignancy in 19 patients, with 30 surgically confirmed PTCs as controls. Based on size, the nodules had been grouped into less than 10mm (group A) and greater than 10 mm (group B). We evaluated conventional parameters and elasticity pattern. Color-scaled elastograms were graded as to stiffness of nodules using an elasticity pattern from I (soft) to IV (stiff).
  
  
  RESULTS
  Degenerating cystic thyroid nodules were similar to PTCs in conventional ultrasonographic findings, but the former frequently showed oval to round in shape (group A, 69.2% vs 18.8%, P=0.017; group B, 66.7% vs 7.14%, P=0.017) and punctuate hyperechoic foci (group A, 61.5% vs 0, P<0.001; group B, 50% vs 0, P<0.001). On real time ultrasound elastography, 7 of 13 degenerating cystic thyroid nodules in group A were pattern I, 5 were pattern II, 1 was pattern III. One degenerating cystic thyroid nodule in group B was pattern II, 5 were pattern III. The area under the curve for elastography was 0.98 in group A (sensitivity 92.3%, specificity 100%, P = 0.002), and 0.88 in group B (sensitivity 16.7%, specificity 100%, P = 0.014).
  
  
  CONCLUSIONS
  As a dependable imaging technique, elastography helps increase the performance in differential diagnosis of degenerating cystic thyroid nodule and malignancy.
authors.affiliation: Department of Ultrasound, Jiang Yuan Hospital Affiliated to Jiangsu Institute of Nuclear Medicine (Key Laboratory of Nuclear Medicine, Ministry of Health/Jiangsu Key Laboratory of Molecular Nuclear Medicine), Wuxi, Jiangsu, China. wuhongxun@jsinm.org
authors.forename: Hong-Xun
authors.initials: HX
authors.lastname: Wu
authors.forename: Bing-Jie
authors.initials: BJ
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Bei-Lin
authors.initials: BL
authors.lastname: Zhu
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Zang
authors.forename: Yue-Long
authors.initials: YL
authors.lastname: Cao
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000601:surgery; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000601:surgery; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000601:surgery; D055815:Young Adult