The value of ultrasound-guided fine-needle aspiration cytology for thyroid nodules: an assessment of its diagnostic potential and pitfalls

• Published in: Surgery today (Tokyo, Japan) Vol. 31; no. 2; pp. 97 - 101
• Main Authors: Ogawa, Y, Kato, Y, Ikeda, K, Aya, M, Ogisawa, K, Kitani, K, Onoda, N, Ishikawa, T, Haba, T, Wakasa, K, Hirakawa, K
• Format: Journal Article
• Language: English
• Published: Japan 01-01-2001
• Subjects: Adenocarcinoma, Follicular - diagnosis; Adenocarcinoma, Follicular - pathology; Adenocarcinoma, Follicular - surgery; Biopsy, Needle - methods; Calcinosis; Diagnosis, Differential; False Negative Reactions; Goiter - diagnosis; Goiter - pathology; Goiter - surgery; Humans; Lymphoma - diagnosis; Lymphoma - pathology; Lymphoma - surgery; Retrospective Studies; Sensitivity and Specificity; Thyroid Neoplasms - diagnosis; Thyroid Neoplasms - pathology; Thyroid Neoplasms - surgery; Thyroid Nodule - diagnosis; Thyroid Nodule - pathology; Thyroid Nodule - surgery; Ultrasonography, Interventional - methods
• ISSN: 0941-1291; 1436-2813
• DOI: 10.1007/s005950170190

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.