The incidence of cancer and rate of false-negative cytology in thyroid nodules greater than or equal to 4 cm in size

Surgery. 2007 Dec;142(6):837-44; discussion 844.e1-3. doi: 10.1016/j.surg.2007.08.012. Epub 2007 Nov 5.

Abstract

Background: High false-negative rates for fine needle aspiration biopsy (FNAB) of thyroid nodules greater than 3 cm have prompted recommendations for diagnostic lobectomy. We considered the presence of a greater than 4 cm nodule an independent indication for thyroidectomy regardless of FNAB results.

Methods: We reviewed clinical data from 223 patients with thyroid nodules greater than or equal to 4 cm operated on from July 2003 to November 2006. Unifocal micropapillary cancer was considered clinically insignificant.

Results: Clinically significant thyroid cancer was frequent, occurring in 57 of 223 patients (26%). Subgroup analysis showed that 43 of 223 patients (19.3%) had carcinoma within the mass and that 7 of 223 patients (3.1%) had significant carcinoma elsewhere in the resected thyroid. Multifocal micropapillary cancer was found in an additional 7 of 223 patients (3.1%). Preoperative FNAB was read incorrectly as benign in 9 of 71 patients with cancer (13%) (16% including multifocal micropapillary carcinoma). Benign FNAB results failed to identify 24 (34%) follicular lesions (including 7 cancers). In patients with preoperative FNAB results categorized as indeterminate lesions, 17 of 43 patients (40%) had carcinoma of the mass on final pathology.

Conclusions: In thyroid nodules greater than or equal to 4 cm, the incidence of carcinoma is high with a high false-negative rate for preoperative benign cytology. Thyroid nodules greater than or equal to 4 cm should be considered for diagnostic lobectomy regardless of FNAB results.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biopsy, Fine-Needle / standards
  • Carcinoma, Papillary / epidemiology*
  • Carcinoma, Papillary / pathology*
  • Carcinoma, Papillary / surgery
  • False Negative Reactions
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Preoperative Care
  • Thyroid Neoplasms / epidemiology*
  • Thyroid Neoplasms / pathology*
  • Thyroid Neoplasms / surgery
  • Thyroid Nodule / epidemiology*
  • Thyroid Nodule / pathology*
  • Thyroid Nodule / surgery
  • Thyroidectomy
  • Thyroiditis, Autoimmune / epidemiology
  • Thyroiditis, Autoimmune / pathology
  • Thyroiditis, Autoimmune / surgery