[Sentinel lymph node detection in patients with early-stage breast cancer: which site of injection in 2011?]

Sentinel lymph node (SLN) mapping and biopsy have emerged as the technique of choice for axillary staging of breast cancer. Several methods have been developed to identify SLNs, including peritumoral or periareolar injection of blue dye or technetium colloid. The optimal site for injection of mapping tracers is controversial in SLN. The peritumoral injection provides information on the deep lymphatic drainage and the internal mammary chain. The advantages of periareolar injection are simplicity, the ability to perform it in non-palpable tumors, and the potential enhancement of uptake via the subareolar lymphatic plexus. The results of multiinstitutional study have indicated that superficial injection (periareolar or peritumoral) is associated with a better identification rate and an equal false-negative rate compared to deep peritumoral (PT) injection. However, the false-negative rate of periareolar injection has not been formally demonstrated.