US-guided fine-needle aspiration biopsy of thyroid nodules: Adequacy of cytologic material and procedure time with and without immediate cytologic analysis

PURPOSE: To compare the adequacy of aspirated material and procedure time when performing ultrasonography-guided fine-needle aspiration biopsy of thyroid nodules with and without immediate cytologic analysis of the aspirated sample. MATERIALS AND METHODS: One hundred twenty-one thyroid nodules were sampled for biopsy in 109 patients. In group A, results of 50 biopsies in which immediate cytologic analysis was performed were retrospectively reviewed for cytologic adequacy. In group B, 50 biopsies were performed without immediate cytologic analysis, and the procedure time was recorded. In group C, 21 biopsies were performed with immediate cytologic analysis, and the procedure time was recorded. Cytologic adequacy rates were compared by using the proportional odds model, and procedure times were compared by using linear regression to adjust for differences in the character of the nodules. RESULTS: For groups A and C (immediate cytologic analysis performed), the adequacy categories included the following results: 39 (55%) satisfactory, 15 (21%) limited, and 17 (24%) unsatisfactory. For group B (immediate cytologic analysis not performed), the adequacy categories included the following results: 25 (50%) satisfactory, 15 (30%) limited, and 10 (20%) unsatisfactory (Wald test, P = .815). The average procedure time was 12.5 minutes for group B and 44.4 minutes for group C (P < .001). CONCLUSION: There was no significant difference in cytologic adequacy whether immediate cytologic analysis of aspirated material was performed or not. The procedure time was significantly shorter when immediate cytologic analysis was not performed.