title: Ultrasound-guided fine-needle aspiration of thyroid nodules measuring less than 5 mm: effects on specimen adequacy and diagnosis.
abstract: OBJECTIVE
  We aimed to assess the adequacy and efficacy of ultrasound (US)-guided fine-needle aspiration (US-FNA) for small solid thyroid nodules (SSTNs) with the largest diameter <5 mm and compared these according to nodule size.
  
  
  METHODS
  Among 656 SSTNs in 569 patients, each SSTN was classified into 1 of 4 groups according to the largest diameter: 1 mm ≤ group A < 2 mm; 2 mm ≤ group B < 3 mm; 3 mm ≤ group C < 4 mm, and 4 mm ≤ group D < 5 mm. We compared the adequacy and efficacy of US-FNA between these groups using histopathologic results as a reference standard.
  
  
  RESULTS
  571 (87.0%) SSTNs were adequately sampled by US-FNA and 200 of these were histopathologically confirmed. The adequacy of US-FNA for SSTNs varied according to the nodule diameter: the smaller the nodule diameter, the lower the diagnostic adequacy. The diagnostic efficacy of US-FNA for SSTNs showed a significant relationship with nodule size: diagnostic efficacy in groups A and B was lower than in groups C and D.
  
  
  CONCLUSIONS
  The adequacy of US-FNA for SSTNs tended to decrease with decreased nodule size, and diagnostic efficacy of US-FNA for SSTNs with the largest diameter <3 mm was lower than for those ≥3 mm.
authors.affiliation: Department of Radiology, Inje University College of Medicine, Gyeongnam, South Korea.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Kim
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Jung
authors.forename: Hyun Sin
authors.initials: HS
authors.lastname: In
authors.forename: Jae Wook
authors.initials: JW
authors.lastname: Eom
authors.forename: Ji Hwa
authors.initials: JH
authors.lastname: Ryu
authors.forename: Young Wook
authors.initials: YW
authors.lastname: Kim
mesh_terms: D044963:Biopsy, Fine-Needle / Q000379:methods*; D003581:Cytodiagnosis / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013048:Specimen Handling; D016606:Thyroid Nodule / Q000175:diagnosis*; D014463:Ultrasonography