title: Sonographic differentiation of thyroid nodules with eggshell calcifications.
abstract: OBJECTIVE
  The purpose of this study was to assess the role of known suspicious sonographic findings and to find other additional sonographic findings to differentiate benign and malignant thyroid nodules with "eggshell" calcifications.
  
  
  METHODS
  Our Institutional Review Board approved this retrospective study, and informed consent was not required. We reviewed sonographic findings of thyroid nodules in 795 patients who underwent thyroid surgery in our institution between August 2006 and February 2007. Ninety-three thyroid nodules with eggshell calcifications in 92 patients were included in this study. Each lesion was evaluated for known suspicious sonographic criteria, including marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape, as well as 2 additional sonographic findings: a hypoechoic halo and disruption of eggshell calcifications (halo and disrupted calcification rim). The sensitivity and specificity based on the sonographic criteria were calculated and compared among the 2 types of criteria.
  
  
  RESULTS
  Among the 93 thyroid nodules, 59 were malignant and 34 were benign. The halo and disrupted calcification rim showed higher sensitivity (62.7% and 76.3%, respectively) than any of the known suspicious sonographic criteria (40.7%, 35.6%, and 55.9%). The combination of both the halo and the disrupted calcification rim showed significantly higher sensitivity (93.2%) than the combination of the known suspicious sonographic criteria (78%; P < .05), although both had the same specificity (64.7%).
  
  
  CONCLUSIONS
  In thyroid nodules with eggshell calcifications but no other calcifications, the findings of a peripheral halo and disruption of the eggshell calcifications may be more useful sonographic predictors of malignancy than hypoechogenicity, microlobulated margins, and a taller-than-wide shape.
authors.affiliation: Department of Radiology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Byung Moon
authors.initials: BM
authors.lastname: Kim
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
authors.forename: Soon Won
authors.initials: SW
authors.lastname: Hong
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Son
authors.forename: Ki Hwang
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult