Fine-needle aspiration biopsy was sensitive for nonfunctional thyroid nodules
ACP J Club. 1995 Jan-Feb;122:20. doi:10.7326/ACPJC-1995-122-1-020
Cochand-Priollet B, Guillausseau P, Chagnon S, et al. The diagnostic value of fine-needle aspiration biopsy under ultrasonography in nonfunctional thyroid nodules: a prospective study comparing cytologic and histologic findings. Am J Med. 1994 Aug;97:152-7.
To determine the diagnostic value of fine-needle aspiration biopsy (FNAB) in patients with nonfunctioning thyroid nodules.
Blinded comparison of cytologic findings using FNAB with histologic findings obtained at surgery in consecutive patients having ultrasound-guided FNAB.
A hospital in France.
132 patients (age range 18 to 32 y, 86% women) had a palpable nonfunctional thyroid nodule that was cold at iodine-123 scintigraphic scan.
Description of test and diagnostic standard
Each patient had FNAB under ultrasonography done by the same radiologist using a high-frequency probe. A tissue core biopsy was also done in 51 of 132 patients. A cytopathologist classified the findings into 4 categories: insufficient material to make a diagnosis; benign tumor; malignant tumor; and suspicious for malignant tumor, including Hürthle cell tumor. All patients having biopsy were referred for surgery regardless of the biopsy results. The diagnostic standard for malignancy was postmortem examination (2 patients) or final histologic examination of specimens obtained at surgery. A second pathologist, blinded to the findings of the first, made the final diagnosis.
Main outcome measures
Sensitivity and specificity of FNAB.
Sensitivity, specificity, and positive and negative likelihood ratios are shown in the Table. Sufficient material for a cytopathologic diagnosis was obtained in 127 of the 132 patients (96%). Tissue core biopsies were available for 51 patients (39%).
Ultrasound-guided fine-needle aspiration biopsy was sensitive, specific, and accurate for detecting the true nature of thyroid nodules, with a low rate for obtaining inadequate material.
Source of funding: Not stated.
For article reprint: Dr. B. Cochand-Priollet, Department of Pathology, Lariboisière Hôpital, 2 rue Ambroise Paré, 75475 Paris Cedex 20, France. FAX 33-149-958-536.
Table. Test characteristics of fine-needle aspiration biopsy in determining benign and malignant thyroid nodules*
|All patients (n = 132)||73%||85%||4.9||0.32|
|Patients for whom sufficient cytology was available (n = 127)||79%||84%||4.9||0.25|
|Excluding patients with insufficient cytology, occult carcinomas, and Hürthle cell tumors (n = 51)||95%||88%||7.9||0.06|
*LRs defined in Glossary and calculated from data in article.
Currently, high-resolution ultrasonography is the method of choice for evaluating small thyroid nodules (1). High-resolution ultrasonography is a noninvasive and relatively inexpensive method that permits careful imaging of the thyroid gland and is more sensitive than physical examination and other imaging techniques. The value of ultrasound-guided aspiration biopsy is now established. Ultrasound-guided biopsy should be used for nodules that are < 1 cm in size or are nonpalpable. For patients who have palpable thyroid nodules, initial biopsy should be palpation-guided and, if unsuccessful, then ultrasound-guided biopsy should be done.
Satisfactory rates using ultrasound-guided FNAB are increased and some investigators have reported rates as high as 90% to 96% (2, 3). Thyroid incidentalomas that are ≥ 1 cm should be biopsied under ultrasound guidance. Lin and colleagues (4) reported that 35% of malignant incidentalomas were correctly identifed using ultrasound-guided FNAB. Other groups (5) have reported an identification rate of 10% for nodules < 1 cm and a rate of 5% for those ≥ 1 cm in diameter.
Overall, ultrasound-guided FNAB is now a useful part of thyroid practice. We recommend it for patients with incidentalomas that need biopsy or when palpation-guided initial FNAB is unsatisfactory (nondiagnostic).
Hossein Gharib, MD
Mayo ClinicRochester, Minnesota, USA