Abstract:

OBJECTIVE: To evaluate the effect of needle size on adequacy of the specimens in fine needle aspiration of thyroid nodules. METHODS: In our institution, various needle sizes have been used in fine needle aspiration of thyroid nodules, ranging from 21 G to 25 G. In this study, we have retrospectively compared the adequacy rates of biopsy specimens in two age-and-sex matched groups of patients. The groups consisted of patients in whom the specimens were collected by the same radiologist, using the same biopsy technique (4-5 needle passes through the nodules), however with different needle size (21 G or 25 G) in each group. Only the solid nodules, or, nodules with solid component, with diameters exceeding 1 cm were included in the study. Aspirations resulting in cystic content of the nodule were excluded. RESULTS: Statistical analysis revealed that rates of specimen adequacy were significantly higher (p=0.002) in biopsies with larger (25 G) needles (22.5% vs. 40.7% in 21 G and 25 G groups, respectively). CONCLUSION: To our knowledge, this is the first study to show that needle size may have an impact on the adequacy rates of the specimens in fine needle aspiration of thyroid nodules. Results are discussed, with suggestions to improve the biopsy results with 25 G needles.

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