title: Cricoid cartilage on sonography in pediatric patients mimics a thyroid mass.
abstract: OBJECTIVE
  The purpose of this study was to describe the sonographic appearance of the uncalcified cricoid cartilage in pediatric patients and illustrate how this can be easily confused with a thyroid mass or residual thyroid tissue after thyroidectomy.
  
  
  METHODS
  We retrospectively reviewed the sonographic and computed tomographic examinations performed on 4 adolescent patients. Two patients had either thyroid cancer or thyroid nodules, and 2 healthy patients were reviewed to show normal anatomy. Results were compared with the clinical and surgical findings in each patient.
  
  
  RESULTS
  Computed tomographic and sonographic examinations showed the normal anatomic relationships and imaging appearance of the cricoid cartilage. Findings from a follow-up sonographic examination on a patient with treated thyroid cancer were initially interpreted as residual thyroid tissue, but another examination revealed that this tissue was actually uncalcified cricoid cartilage. Another patient who had intraoperative sonography verified these findings.
  
  
  CONCLUSIONS
  Uncalcified cricoid cartilage in a pediatric patient appears on sagittal sonography as a round or ovoid structure with variable echogenicity, located posteromedial to the thyroid gland. Awareness of this structure's sonographic appearance should prevent unnecessary biopsy or surgery.
authors.affiliation: Department of Diagnostic Imaging, Rhode Island Hospital, Brown University School of Medicine, 593 Eddy St, Providence, Rhode Island 02903, USA. jdonohoo@lifespan.org
authors.forename: Jay H
authors.initials: JH
authors.lastname: Donohoo
authors.forename: Michael T
authors.initials: MT
authors.lastname: Wallach
mesh_terms: D000293:Adolescent; D003413:Cricoid Cartilage / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D014463:Ultrasonography