Thyroid nodules over 4 cm do not have higher malignancy or benign cytology false-negative rates

Endocrine. 2019 Nov;66(2):249-253. doi: 10.1007/s12020-019-01964-3. Epub 2019 May 29.


Purpose: Whether thyroid nodules 4 cm or larger with benign cytology carry a higher risk of malignancy, and should be managed differently than smaller nodules remains controversial. We aimed to evaluate the malignancy rate and benign cytology false-negative rate in thyroid nodules ≥4 cm compared with those <4 cm.

Methods: All thyroidectomies between January 2010 and December 2014 were reviewed. Patient demographics, preoperative sonographic nodule size, fine needle aspiration cytology (FNAC), and final surgical pathology results were compared for index nodules ≥4 vs. <4 cm.

Results: A total of 490 index nodules with preoperative FNAC were identified. A total of 137 nodules were ≥4 cm and 353 nodules were <4 cm. The prevalence of carcinoma was lower (23 vs. 53%) in nodules ≥4 vs. <4 cm (p < 0.0001). The false-negative rate of benign FNAC for ≥4 and <4 cm index nodule was 5.2% and 5.9%, respectively (p = 1.000).

Conclusions: This study shows that thyroid nodules ≥4 cm do not have a higher malignancy rate at surgery nor higher benign cytology false-negative rate than smaller nodules. Thyroid nodules over 4 cm do not require resection, to rule out malignancy, based on size alone.

Keywords: False-negative rate; Size; Thyroid carcinoma; Thyroid nodule; ≥4 cm.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biopsy, Fine-Needle
  • Cytodiagnosis
  • False Negative Reactions
  • Female
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Thyroid Gland / diagnostic imaging
  • Thyroid Gland / pathology*
  • Thyroid Gland / surgery
  • Thyroid Neoplasms / diagnostic imaging
  • Thyroid Neoplasms / pathology*
  • Thyroid Neoplasms / surgery
  • Thyroid Nodule / diagnostic imaging
  • Thyroid Nodule / pathology*
  • Thyroid Nodule / surgery
  • Thyroidectomy
  • Ultrasonography