Objective To investigate the application value of ultrasound-guided fine needle aspiration (FNA) in the diagnosis of internal mammary nodes (IMN) in breast cancer.

Methods A total of 160 breast cancer patients with suspected IMN were selected as the study subjects. All patients underwent IMN puncture biopsy under ultrasound guidance, with 88 cases in core needle biopsy (CNB) group and 72 cases in FNA group. The diagnostic efficacy of FNA and CNB for IMN was analyzed and compared according to pathological diagnosis results.

Results The maximum diameter and maximum thickness of IMN in the FNA group were smaller than those in the CNB group (P < 0.05). There was no statistically significant difference in the classification of IMN diagnosed by puncture between the two groups (P>0.05). There were also no statistically significant differences in the unsatisfactory rate of puncture specimens and the positive rate of IMN between the two groups (P>0.05). The consistency test results showed good consistency of the CNB and FNA groups compared with pathological diagnosis (Kappa>0.70); compared with the CNB group, the consistency of the FNA group was higher (Kappa=0.890). There were no statistically significant differences in the sensitivity, specificity, and positive predictive value of IMN diagnosis between the CNB and FNA groups (P>0.05); the negative predictive value of the CNB group was lower than that of the FNA group, and the false-negative rate was higher (P < 0.05). Eight cases (9.09%) in the CNB group developed puncture complications, including 6 cases of mild or asymptomatic pneumothorax and 2 cases of intermuscular hemorrhage, with relatively mild symptoms. No puncture complications occurred in the FNA group.

Conclusion Ultrasound-guided FNA has a high efficacy in the qualitative diagnosis of IMN in breast cancer, with low puncture risk and fewer complications, making it more suitable for IMN puncture biopsy in special anatomical locations.