title: False negative cytology in large thyroid nodules.
abstract: BACKGROUND
  Controversy exists regarding the accuracy of fine-needle aspiration (FNA) in large thyroid nodules. Recent surgical series have documented false-negative rates ranging from 0.7 to 13 %. We examined the accuracy of benign FNA cytology in patients with thyroid nodules ≥3 cm who underwent surgical resection and identified features characteristic of false-negative results.
  
  
  METHODS
  We retrospectively studied all thyroidectomy specimens between January 2009 and October 2011 and identified nodules ≥3 cm with corresponding benign preoperative FNA cytology. We collected clinical information regarding patient demographics, nodule size, symptoms, sonographic features, FNA results, and final surgical pathology. For comparison, we analyzed nodules <3 cm from this cohort also with benign FNA cytology.
  
  
  RESULTS
  A total of 323 nodules with benign preoperative cytology were identified. Eighty-three nodules were <3 cm, 94 nodules were 3-3.9 cm, and 146 nodules were ≥4 cm in size. The false-negative rate was 11.7 % for all nodules ≥3 cm and 4.8 % for nodules <3 cm (p = 0.03). Subgroup analysis of nodules ≥3 cm revealed a false-negative rate of 12.8 % for nodules 3-3.9 cm and 11 % for nodules ≥4 cm. Age ≥55 years and asymptomatic clinical status were the only patient characteristics that reached statistical significance as risk factors. Final pathology of the false-negative specimens consisted mainly of follicular variant of papillary thyroid cancer and follicular thyroid cancer.
  
  
  CONCLUSIONS
  When referred for thyroidectomy, patients with large thyroid nodules demonstrate a modest, yet significant, false-negative rate despite initial benign aspiration cytology. Therefore, thyroid nodules ≥3 cm may be considered for removal even when referred with benign preoperative cytology.
authors: Department of Surgery, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA.
authors: Wesley H
authors: WH
authors: Giles
authors: Reid A
authors: RA
authors: Maclellan
authors: Atul A
authors: AA
authors: Gawande
authors: Daniel T
authors: DT
authors: Ruan
authors: Erik K
authors: EK
authors: Alexander
authors: Francis D
authors: FD
authors: Moore
authors: Nancy L
authors: NL
authors: Cho
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000175:diagnosis* / Q000601:surgery; D044963:Biopsy, Fine-Needle; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000601:surgery; D003581:Cytodiagnosis; D005188:False Negative Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000601:surgery; D013965:Thyroidectomy