[Breast cancer. current use of the extra-pleural exploration of the internal mammary chain]. / Cáncer de mama: alcances actuales y vigencia de la exploración estadificatoria extra-pleural de la cadena mamaria interna.

The interest to know the Internal Mammary Chain (IMC) Involvement , is that it is a lymphatic filter as primary as the axilla. Anatomic-surgical fundaments, were presented for their exploration. Fifty (50) pectus-sternal, analizing the number of nodes (average 9,7 per specimen), located preferably in the three first intercostal spaces, were studied. In the second phase IMC with a staging criterion and extrapleural way, resecting 1 or 2 costal cartilages, were explored. In 78 patients, pathological-anatomy correlation between IMC and the axilla, we observed 6% positive IMC with negative axilla. More recently in the era of the setinel node, we have explored IMC in 44 patients through intercostal spaces and without cartilages resection. In 28 patients we performed through radioisotopic way and gamma probe and in the remaining 16, through anatomic search if the tumor was either upper mid or lower. The most frequent spaces explored were in the 2nd and 3rd; 2,27 nodes average per patient. The pathological-anatomy between IMC and the axilla revealed the following results: axilla (-) IM (-): 59%; axilla (+) MI (-): 25%; axilla (+) IM (+): 11% and axilla (-)IM (+): 5%. We concluded that this is a non-aggressive method, with an excellent tolerance that allows the evaluation of another filter as primary as the axilla and that together they represent the best systemic disease prognostics. We believe that its exploration is justified in those cases in which the histological result , correlated with the axilla, allows a therapeutic approach change.