In patients with breast cancer, chest wall involvement means involvement of any one of the following structure except

.Spread into the Deeper Plane * Into pectoralis major muscle (is confirmed by observing the restricted mobility of the swelling while contracting the PM muscle). * Into latissimus dorsi muscle (extending the shoulder against resistance). * Into serratus anterior (by pushing the wall with hands without flexing the elbow). *Into the chest wall (breast will not fall forward when leaning forward, and while raising the arm above the shoulder, breast will not move upwards as it is fixed to the chest wall). ref:SRB&;s manual of surgery,ed 3,pg no 472