title: Thyroid cysts treated with ethanol ablation can mimic malignancy during sonographic follow-up.
abstract: OBJECTIVE
  We aimed to assess long-term ultrasound (US) findings after US-guided percutaneous ethanol ablation (EA) in benign thyroid cysts and predominantly cystic thyroid nodules.
  
  
  METHODS
  Forty patients with thyroid cysts (n = 14) and predominantly cystic thyroid nodules (n = 26) underwent long-term US follow-up (range, 12-36 months; mean, 18.2 months) after EA. US images of 40 post-EA nodules were retrospectively investigated to study the reduction in nodule volume and detailed US appearance.
  
  
  RESULTS
  On follow-up US, post-EA nodules showed the following features: Marked hypoechogenicity (n = 28), spiculated margin (n = 7), microcalcifications (n = 6), taller-than-wide shape (n = 2), centrally predominant vascularity (n = 3), no vascularity (n = 31), mixed vascularity (n = 3), and peripheral vascularity (n = 3). Post-EA nodules were diagnosed by US as benign (n = 3), probably benign (n = 2), borderline (n = 5), possibly malignant (n = 20), and malignant (n = 10). No statistical difference in the incidence of malignant US findings was observed between thyroid cysts and predominantly cystic thyroid nodules (p > 0.05, Fisher's exact test).
  
  
  CONCLUSIONS
  Long-term follow-up US after successful EA of benign thyroid cysts and predominantly cystic thyroid nodules revealed a high incidence of findings that are usually associated with malignancy. Recognizing these consequences of the procedure would help avoid unnecessary FNA on post-EA nodules.
authors: Department of Radiology, Myongji Hospital, Kwandong University, College of Medicine, Seoul, South Korea.
authors: Noh Hyuck
authors: NH
authors: Park
authors: Dong Wook
authors: DW
authors: Kim
authors: Hee Jin
authors: HJ
authors: Park
authors: Eun Ja
authors: EJ
authors: Lee
authors: Ji Sung
authors: JS
authors: Park
authors: Sung Il
authors: SI
authors: Park
authors: Jong Myon
authors: JM
authors: Bae
authors: Jun Hwa
authors: JH
authors: Lee
mesh_terms: D055011:Ablation Techniques; D000293:Adolescent; D000328:Adult; D003560:Cysts / Q000000981:diagnostic imaging* / Q000601:surgery; D003937:Diagnosis, Differential; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013959:Thyroid Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000601:surgery; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D000431:Ethanol