Objective: To assess the value of repeating a biopsy when the initial thyroid fine-needle aspiration (FNA) biopsy is nondiagnostic.
Methods: Between 1990 and 2003, 4,311 thyroid FNAs were performed at the Cleveland Clinic Foundation, of which 220 (5%) were nondiagnostic. Among 189 patients whose medical records were available for retrospective review, 106 underwent a repeated FNA (FNA #2), and 14 had a second repeated FNA (FNA #3). Thyroid ultrasonography was used in the evaluation in 113 FNAs.
Results: The first and second repeated FNAs were diagnostic in 58% (62 of 106 patients) and 50% (7 of 14 patients), respectively. The rate of malignant disease in patients with no repeated FNAs versus 1 or more repeated FNAs was 4.8% (4 of 83) versus 11.3% (12 of 106), respectively. Ultrasound-guided FNA yielded a diagnosis among 33 of 113 biopsies (29.2%), and FNA without ultrasound guidance provided a diagnosis in 30 of 159 biopsies (18.9%). Thus, the use of thyroid ultrasonography significantly improved the likelihood of establishing a diagnosis (P = 0.017). We found that repeating the FNA up to 2 times provides a diagnosis in up to 60% of cases.
Conclusion: The overall prevalence of thyroid cancer in patients with nondiagnostic FNA is not trivial--8.5% in our study group of 189 patients. An aggressive approach toward nondiagnostic FNA biopsies is recommended, with performance of at least 2 repeated FNA biopsies, preferably with the help of ultrasound guidance.