surgical classification of axillary lymph node

Surgical classification
The surgical classification is used in axillary dissection for breast cancer. It is entirely based on the relationship of the lymph nodes to pectoralis minor. The levels usually refer to a dissection, so a 'level 3 dissection' will have removed nodes from levels 1, 2 and 3.

Level 1 nodes
Level 1 includes all those nodes inferior to the inferolateral border of pectoralis minor. It is usually comprised of the lateral, anterior and posterior nodes.

Level 2 nodes
Level 2 consists of those nodes posterior to pectoralis minor. It includes the central nodes and some of the apical nodes.

Level 3 nodes
Level 3 consists of those nodes beyond the superior border of pectoralis minor. It includes the remaining apical nodes and infraclavicular nodes.

Sentinel node
A sentinel node is the first node to drain from a particular area. In breast cancer, it refers to the first node to drain from that portion of the breast. This is usually an anterior node.