The value of ultrasound-guided fine-needle aspiration cytology for thyroid nodules: an assessment of its diagnostic potential and pitfalls.
This study was conducted to assess the diagnostic potential and pitfalls of performing fine-needle aspiration cytology (FNAC) for thyroid nodules. We retrospectively analyzed 1,012 aspirated samples obtained from 806 thyroid nodules by the ultrasound (US)-guided method. Of these 806 nodules, 226 (31%) had been surgically treated, 152 (67%) of which were histologically diagnosed as malignant. The rate of sufficient aspirate was 82%, being lower in nodules with a diameter of less than 5mm (73%, P = 0.10); either calcified (77%, P = 0.043) or benign (72%, P = 0.0002). The accuracy of FNAC was 75%, the rate of indeterminate diagnosis was 16%, the false negative rate was 13%, and the positive malignancy rate was 99%. The rate of indeterminate diagnosis was higher in adenomatous goiter, follicular carcinoma, and malignant lymphoma, at P = 0.015, P = 0.0008, and P = 0.035, respectively. The accuracy was lower in follicular carcinoma and malignant lymphoma (both at P = 0.013). Sufficient aspirate was finally obtained from 701 (87%) of the 806 nodules by repeated aspiration. Of 152 malignant nodules, 28 (18%) were diagnosed after two or more aspirations, and the accuracy was improved to 81% by repeating the procedure. These findings indicated that repeated aspiration may be a simple and effective method of improving the diagnostic potential of FNAC.
Ogawa
Y
Y
First Department of Surgery, Osaka City University Medical School, Osaka, Japan.
Kato
Y
Y
Ikeda
K
K
Aya
M
M
Ogisawa
K
K
Kitani
K
K
Onoda
N
N
Ishikawa
T
T
Haba
T
T
Wakasa
K
K
Hirakawa
K
K
D018263:Adenocarcinoma, Follicular / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D001707:Biopsy, Needle / Q000379:methods; D002114:Calcinosis; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D006042:Goiter / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D016606:Thyroid Nodule / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D018084:Ultrasonography, Interventional / Q000379:methods*