title: Diagnostic lobectomy is not routinely required to exclude malignancy in thyroid nodules greater than four centimetres.
abstract: BACKGROUND
  Surgical excision has been recommended as a diagnostic test for thyroid nodules ≥ 4 cm, due to the supposedly higher rate of cancer in larger nodules and the higher reported false-negative rates of fine-needle aspiration cytology (FNAC) testing (>10%). The aims of this study are to determine the prevalence of thyroid cancer in nodules ≥ 4 cm, to examine if a relationship between increasing nodule size and malignancy rate was present and to study the accuracy of preoperative FNAC diagnosis.
  
  
  METHODS
  Retrospective analysis of data from patients with thyroid nodules ≥ 4 cm undergoing surgical resection between 1994 and 2008. Malignancy rates, cytology results and indications for surgery were analysed.
  
  
  RESULTS
  A total of 223 patients with thyroid nodules ≥ 4 cm underwent thyroid resection between 1994 and 2008. The overall prevalence of thyroid cancer was 7.2% (95% confidence interval (CI): 4.2-11.4%). The malignancy rate did not vary significantly with increasing nodule size. The sensitivity of FNAC was 93.8% (95% CI: 69.8-99.8%), while the specificity of FNAC was 62.2% (95% CI: 54.9-69.2%). The most common indicator for surgery was compression symptoms. A positive FNAC test was the most significant indicator of underlying malignancy, with a likelihood ratio of 2.5 (95% CI: 2.0-3.1).
  
  
  CONCLUSIONS
  Many patients with large thyroid nodules undergo thyroidectomy for symptom relief alone, regardless of their FNAC results. In such patients where other clinical indicators for thyroidectomy are not present, a benign FNAC result can reassure both patient and surgeon that mandatory surgical excision is not needed to exclude malignancy.
authors.affiliation: Monash University Endocrine Surgery Unit, Alfred Hospital, Melbourne, Australia.
authors.forename: Mariolyn D
authors.initials: MD
authors.lastname: Raj
authors.forename: Simon
authors.initials: S
authors.lastname: Grodski
authors.forename: Stacey
authors.initials: S
authors.lastname: Woodruff
authors.forename: Meei
authors.initials: M
authors.lastname: Yeung
authors.forename: Eldho
authors.initials: E
authors.lastname: Paul
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Serpell
mesh_terms: D018263:Adenocarcinoma, Follicular; D018249:Adenoma, Oxyphilic; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D002277:Carcinoma; D018278:Carcinoma, Neuroendocrine; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000077273:Thyroid Cancer, Papillary; D065646:Thyroid Carcinoma, Anaplastic; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D016606:Thyroid Nodule / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy