[Interest of periareolar injection for colorimetric detection of sentinel node in breast cancer].

Most teams working on sentinel node biopsy in the treatment of breast cancer inject either radioactive colloid or vital blue dye around the primary tumour. Many anatomical studies and lymphoscintigraphical studies, some very old, have shown that the lymphatic drainage of the breast is collected first in the periareolar plexus of Sappey, then routed to the axilla in 95% of cases, via one or two primary collectors. In a series of 94 breast cancers measuring less than 3 cm, with any palpable axillary lymph node, 2 ml of patent blue was injected intradermally around the areola, at the two meridians around the tumor. The sentinel node was identified in 89 cases (94,7%), regardless of the location of the primary tumor. All the sentinel nodes were located in the lower axilla. An average of 1.6 nodes were found per patient. In 41 cases, axillary lymph node dissection was performed either immediately (5 technical failures, 9 positive frozen section) or delayed only if the sentinel node was positive, either on standard H&E staining or on immunohistochemistry (27 cases). Thus, axillary lymph node dissection was not performed in 48 patients (55%). In positive node patient, the sentinel node was the only positive lymph node in 20 patients (55%). For 5 positive node patients, axillary lymph node dissection was not performed: poor vital status (2 micro-metastatic nodes) or by decision of patient (3 IHC positive nodes). With this periareolar injection procedure, the rate of detection is highly satisfactory and is comparable to that usually published with peritumoral injection. This procedure seems appropriate in all cases, regardless of the topography, the size or the multifocality of breast cancer.