Controversies in the use of sentinel nodes: microinvasion, post surgery and after preoperative systemic treatment.

In the past 10 years, sentinel lymph node biopsy (SLNB) has become a safe and accurate method for axillary staging. Several recent publications worldwide have been progressively elucidating old controversies. The list of clinical scenarios in which SLNB was initially contraindicated seems to be dwindling as experience with this technique increases. Here we discuss the suitability of SLNB in the settings of microinvasive cancer, after breast or axillary surgery and after neoadjuvant chemotherapy.