[Internal mammary node biopsy in breast cancer].

BACKGROUND & OBJECTIVE: Internal mammary node (IMN) is an important lymphatic metastasis pathway in breast cancer. Its status may affect the staging, treatment, prognosis, and outcome evaluation of breast cancer. This study was to discuss the significance of internal mammary sentinel node biopsy (IMSNB), IMN dissection via intercostal spaces, and IMN micro-metastasis detection in breast cancer.

METHODS

A total of 38 consecutive patients with primary breast cancer received mastectomy in Cancer Center of Sun Yat-sen University from Dec. 2004 to May 2006. IMSNB was guided by radionuclide tracking method, followed by IMN dissection via the first to forth intercostal spaces. After routine pathologic examination for all the removed IMNs, the negative ones were submitted to further micro-metastasis detection by immunohistochemistry (IHC) combined with multilayer section technique.

RESULTS

Of the 38 patients, 17 (44.7%) had internal mammary sentinel nodes (IMSNs). Of the 17 patients, 4 had IMSN metastasis detected by routine pathology, 1 had IMSN micro-metastasis, and 2 had isolated tumor cells in IMSNs, while the remaining 10 had no metastasis. The results of IMSNB were accordant to the results of IMN dissection. Of the 21 (55.3%) patients had no IMSN identified, 5 had IMN metastasis by routine pathology after IMN dissection, and 16 had no metastasis.

CONCLUSIONS

When IMSNs are identified, they can predict the IMN status well. While for the patients had no IMSN identified, IMN dissection should be performed, especially for those more likely to have metastasis, to decrease the false negative rate. IHC combined with multilayer section technique tends to search out micro-metastasis.