Contribution of minute axillary lymph nodes to accurate staging for patients with breast cancer

BACKGROUND: Axillary lymph node metastasis is a very important metastatic pathway in breast cancer and its accurate detection is important for staging tumour and guiding therapy. However, neither the accuracy of routine detection of lymph node in surgical specimens nor the significance of minute lymph node with metastases in breast cancer is clear. A modified method for conveniently detecting minute lymph node in specimens of axillary dissections in patients with breast cancer was used to analyze their influence on staging breast cancer. METHODS: Lymph nodes in fresh, unfixed, specimens of axillary dissections from 127 cases of breast cancer were detected routinely. Then the axillary fatty tissues were cut into 1 cm thick pieces, soaked in Carnoy's solution for 6 to 12 hours, taken out and put on a glass plate. Minute lymph nodes were detected by light of bottom lamp and examined by routine pathology. RESULTS: Lymph nodes (n = 2483, 19.6 +/- 8.0 per case) were found by routine method. A further 879 lymph nodes up to 6 mm (781 < 3 mm, 6.9 +/- 5.3 per case, increasing mean to 26.5 +/- 9.7) were found from the axillary tissues after soaking in Carnoy's solution. By detection of minute lymph nodes, the stages of lymph node metastasis in 7 cases were changed from pathological node (pN) stage pN(0) to pN(1) in 4 cases, from pN(1) to pN(2) in 2 and from pN(2) to pN(3) in 1. CONCLUSIONS: The accurate staging of axillary lymph node metastasis can be obtained routinely with number of axillary lymph nodes in most cases of breast cancer. To avoid neglecting minute lymph nodes with metastases, small axillary nodes should be searched carefully in the cases of earlier breast cancer with no swollen axillary nodes. Treatment with Carnoy's solution can expediently detect minute axillary nodes and improve the accurate staging of lymph nodes in breast cancer.