title: Description and Comparison of the Sonographic Characteristics of Poorly Differentiated Thyroid Carcinoma and Anaplastic Thyroid Carcinoma.
abstract: OBJECTIVE
  Although poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma account for a substantial portion of the morbidity and mortality associated with thyroid cancer, a chance of a cure exists with aggressive treatment, especially in patients with poorly differentiated thyroid carcinoma. The goal of this study was to evaluate the sonographic characteristics of poorly differentiated thyroid carcinoma and to compare the sonographic findings of poorly differentiated and anaplastic thyroid carcinomas.
  
  
  METHODS
  The study included 29 patients with 30 poorly differentiated thyroid carcinomas and 26 patients with 26 anaplastic thyroid carcinomas. Two radiologists retrospectively reviewed sonographic findings. Clinical and sonographic findings were compared between poorly differentiated and anaplastic thyroid carcinomas by univariate and multivariate analyses.
  
  
  RESULTS
  In the group of patients with poorly differentiated thyroid carcinoma, the mean age was 53.7 years (range, 14-73 years), and the mean tumor size was 3.6 cm (range, 0.6-10.0 cm). The common sonographic findings of poorly differentiated thyroid carcinoma were heterogeneous echogenicity (93.3%), solitary nodules (80.0%), a circumscribed margin (63.3%), an oval-to-round shape (63.3%), and hypoechogenicity (60.0%). A circumscribed margin (P = .003) and an oval-to-round shape (P = .015) were significantly more frequent in poorly differentiated thyroid carcinoma than in anaplastic thyroid carcinoma. In the multivariate analysis, only the circumscribed margin on sonography was an independent predicting factor for poorly differentiated thyroid carcinoma (odds ratio, 4.642).
  
  
  CONCLUSIONS
  Both poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma commonly present as a relatively large malignant mass on sonography; however, poorly differentiated thyroid carcinoma showed a significantly higher incidence of a circumscribed margin and an oval-to-round shape than anaplastic thyroid carcinoma. Knowledge of sonographic characteristics will be useful for differentiation of poorly differentiated and anaplastic thyroid carcinomas.
authors.affiliation: Department of Radiology and Center for Imaging Science, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Soo Yeon
authors.initials: SY
authors.lastname: Hahn
authors.affiliation: Department of Radiology and Center for Imaging Science, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea helena35@hanmail.net.
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Shin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D065646:Thyroid Carcinoma, Anaplastic / Q000000981:diagnostic imaging*; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult
keywords: anaplastic thyroid carcinoma; head and heck ultrasound; poorly differentiated thyroid carcinoma; sonography