<prompt> Sentinel lymph node is defined asPrimary LN draining tumorLN which is first excised during MRMLN nearest to tumorNone  <response>: The first axillary lymphnode draining the breast by direct drainage is designated as sentinel lymph node. SLN is first node involved by tumour cells and presence or absence of its histological involvement when assesed will give a predictive idea about fuher spread of tunour to other nodes. SRBs Manual of Surgery.Edition -5. Pg no:543 