Ultrasound guidance improves the adequacy of our preoperative thyroid cytology but not its accuracy.
OBJECTIVE
Our thyroid cytology audit results of 1990-1995 showed an unsatisfactory rate of 43.1% and prediction of neoplasia with a sensitivity of 86.8%. Increasingly, ultrasound scan (USS)-guided core sampling for cytology is proving a valuable tool instead of freehand fine needle aspiration (FNA) or following unsatisfactory freehand FNA. We present the results of freehand FNA and USS-guided core samples for cytology in two separate patient groups in our centre.


METHODS
Patients who had a thyroid resection and preoperative thyroid cytology in our institution between 1996 and 2002 were included. The histological diagnoses were correlated with the preceding cytology results.


RESULTS
A total of 450 FNAs were performed on 394 patients. Freehand FNAs were performed for 348 (77.3%) samples and USS-guided core for 102 (22.7%) samples; 121 (26.8%) were repeat aspirates performed on 45 patients. Using aspiration cytology (AC) grading, freehand FNA was cytologically inadequate (AC0 or AC1) in 34.8% cases whereas USS-guided core was inadequate in 17.6% cases (P = 0.001). Freehand FNA (AC3, AC4, AC5) predicted neoplasia with a sensitivity of 83.2%, specificity of 46.6%, accuracy of 63.0%, positive predictive value of 56.0% and negative predictive value of 77.1%. USS-guided core sample for cytology (AC3, AC4, AC5) predicted neoplasia with a sensitivity of 93.5%, specificity of 26.0%, accuracy of 51.9%, positive predictive value of 43.9% and negative predictive value of 86.7%.


CONCLUSIONS
Although USS-guided core provides more satisfactory specimens than freehand FNA, in our centre it does not provide increased accuracy.
Mehrotra
P
P
School of Surgical and Reproductive Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK. pallavi.mehrotra@ncl.ac.uk
Viswanathan
H
H
Johnson
S J
SJ
Wadehra
V
V
Richardson
D L
DL
Lennard
T W J
TW
D044963:Biopsy, Fine-Needle / Q000379:methods; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012680:Sensitivity and Specificity; D013959:Thyroid Diseases / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D013965:Thyroidectomy; D014463:Ultrasonography / Q000379:methods