Breast cancer in women: evaluation of benign and malignant axillary lymph nodes with contrast-enhanced ultrasound.

PURPOSE: We assessed the value of contrast-enhanced US for differentiating between benign and malignant axillary lymph nodes in breast cancer. MATERIALS AND METHODS: A total of 120 axillary lymph nodes in 92 patients with breast cancer were studied. All patients underwent grayscale US examination, unenhanced and enhanced color and power Doppler US, and enhanced grayscale harmonic US examination. RESULTS: The mean size of the 120 axillary lymph nodes was 1.5 cm (range 0.5 - 3.4 cm). Of all 120 axillary lymph nodes studied, 80 (67 %) were malignant and 40 (33 %) were benign according to pathological examination. The total number of vessels in baseline US did not increase between benign and malignant lymph nodes (3.3 +/- 2.2 vs. 5.4 +/- 4.0; p > 0.05). The total number of peripheral vessels was 0.5 +/- 0.8 for benign lymph nodes vs. 2.0 +/- 1.7 for malignant lymph nodes (p > 0.05). Enhanced US studies showed enhancement in both benign and malignant lymph nodes after contrast administration with a significantly higher degree of enhancement in malignant lymph nodes (p < 0.01). The total number of vessels was significantly higher in malignant lymph nodes after contrast administration (17.3 +/- 8.0 vs. 8.2 +/- 5.1, p < 0.01). Malignant lymph nodes demonstrated longer contrast enhancement duration compared to benign lymph nodes. CONCLUSION: This preliminary data shows that contrast-enhanced US can differentiate between benign and malignant lymph nodes in breast cancer.