The value of sonographically guided fine-needle aspiration in the diagnosis of small lymph

Background: To analyze the diagnostic value of ultrasound-guided fine-needle aspiration (FNA) biopsy for lymph nodes with short-axis diameters <= 1 cm and to investigate whether the short-axis diameter influences the results of FNA biopsy. Methods: The cytological results of ultrasound-guided FNA lymph node biopsies in 1,242 cases treated at our hospital between December 2015 and June 2017 were retrospectively analyzed. The results were compared with the final diagnostic results of the cases (988 cases had core-needle biopsies, and 254 cases were followed-up for more than six months) to explore the diagnostic value of ultrasound-guided FNA for small lymph nodes. Results: The sensitivities, specificities and accuracies of ultrasound-guided FNA were 99.6%, 99.5% and 99.5% for small lymph nodes with short-axis diameters <= 1 cm and 97.2%, 94.4% and 96.4% for lymph nodes with short-axis diameters >1 cm, respectively. No significant differences were detected between the two groups (P>0.05). Lymph nodes with short-axis diameters <= 1 cm were divided into three groups according to the following diameters: 0.7 cm <= short-axis diameter <= 1 cm, 0.5 cm <= short-axis diameter <0.7 cm, and short-axis diameter <0.5 cm. The sensitivities of ultrasound-guided FNA for these three groups were 99.6%, 99.5% and 98.0% respectively; the specificities were 99.5%, 99.0% and 98.0%, respectively; and the accuracies were 99.8%, 99.3% and 99.0%, respectively. The differences in accuracy between the three groups were significant (P<0.05), while the differences in sensitivity and specificity were not significant (P>0.05). Conclusions: The diagnostic results of ultrasound-guided FNA for small lymph nodes are not affected by the short-axis diameter. For lymph nodes with short-axis diameters <= 1 cm, the accuracy decreases as the short-axis diameter decreases, but FNA still has a high diagnostic accuracy for these small lymph nodes.