title: Ultrasound scan-guided core sampling for diagnosis versus freehand FNAC of the thyroid gland.
abstract: OBJECTIVE
  Freehand fine needle aspiration cytology (FNAC) is an obligatory investigation of the thyroid nodule. Between 5.0-43.1% of FNAC samples are reported as being initially unsatisfactory. In our unit, thyroid freehand FNAs are performed with a small needle (21 or 23G). Non-dominant nodules as part of multinodular goitres, difficult to palpate nodules or nodules with previously unsatisfactory freehand FNACs are sampled under ultrasound scan (USS) guidance with the larger 20G cutting core sampling technique. We aimed to compare the satisfactory sampling rate and safety of the two different methods.
  
  
  METHODS
  Cytology forms were reviewed for 262 freehand FNACs and USS-guided core samples, performed in our unit over a two-year interval (1 July 1999 to 30 June 2001).
  
  
  RESULTS
  Ultrasound-guided core samples for cytology were unsatisfactory (AC0-1) in 19/121 (15.6%) of the cases, compared with 66/141 (46.8%) of freehand FNACs (p value = < 0.0001). Ten out of eleven patients (91%) had a satisfactory USS-guided core after an unsatisfactory freehand FNA; 7/15 patients (46.7%) had satisfactory repeat freehand FNACs following an initial unsatisfactory freehand FNAC (p value = 0.0191). There were no complications as a result of either freehand FNAC or USS-guided core sampling.
  
  
  CONCLUSIONS
  USS-guided cores provided more satisfactory samples for assessment than freehand FNACs. The USS-guided technique is safe despite the use of the larger cuffing needle. The USS-guided core sampling was also a useful tool for repeat thyroid nodule sampling after an unsatisfactory freehand FNAC.
authors.affiliation: University of Newcastle upon Tyne, London. Pallavi.Mehrotra@ncl.ac.uk
authors.forename: P
authors.initials: P
authors.lastname: Mehrotra
authors.forename: J G H
authors.initials: JG
authors.lastname: Hubbard
authors.forename: S J
authors.initials: SJ
authors.lastname: Johnson
authors.forename: D L
authors.initials: DL
authors.lastname: Richardson
authors.forename: R
authors.initials: R
authors.lastname: Bliss
authors.forename: T W J
authors.initials: TW
authors.lastname: Lennard
mesh_terms: D044963:Biopsy, Fine-Needle; D001707:Biopsy, Needle / Q000379:methods*; D006801:Humans; D008485:Medical Audit; D015983:Selection Bias; D013961:Thyroid Gland / Q000473:pathology*; D016606:Thyroid Nodule / Q000473:pathology*; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods