Question

A patient is found to have a melanoma originating in the skin of the left forearm. After removal of the tumor from the forearm, all axillary lymph nodes lateral to the medial edge of the pectoralis minor muscle are removed. Which axillary nodes would NOT be removed?

• A. Apical lymph nodes
• B. Central lymph nodes
• C. Lateral lymph nodes
• D. Pectoral lymph nodes

Hint:

Apical nodes lie medial to the medial border of pectoralis minor, so a dissection stopping at that medial edge spares them.

Answer 1

The Correct Option is A

Step 1: The axillary lymph nodes are grouped surgically by their relation to the pectoralis minor. Level I lies lateral to the lateral border of the muscle, level II lies behind the muscle (between its lateral and medial borders), and level III lies medial to the medial border of the muscle.

Step 2: The surgeon removed all nodes lateral to the MEDIAL edge of the pectoralis minor. This clears everything up to and including the nodes behind the muscle - that is, the lateral (brachial), pectoral (anterior), central and subscapular (posterior) groups.

Step 3: The apical (subclavicular) nodes sit MEDIAL to the medial border of the pectoralis minor. Since only nodes lateral to that medial edge are removed, the apical nodes lie beyond the dissection and are left behind.

Step 4: The central, lateral and pectoral nodes are all lateral to the medial edge and so are removed. Therefore the apical lymph nodes would not be removed.