Chapter 55: Breast- Anatomy of the Breast and Axilla

Question 1

What four nerves must the surgeon be aware of during an axillary dissection?

Answer 1

1. Long thoracic nerve
2. Thoracodorsal nerve
3. Medial pectoral nerve
4. Lateral pectoral nerve

Question 2

Describe the location of these nerves and the muscle each innervates:

Long thoracic nerve

Answer 2

• Courses along the lateral chest wall in midaxillary line on serratus anterior muscle
• innervates serratus anterior muscle

Question 3

Describe the location of these nerves and the muscle each innervates:

Thoracodorsal nerve

Answer 3

• Courses lateral to long thoracic nerve on latissimus dorsi muscle
• innervates latissimus dorsi muscle

Question 4

Describe the location of these nerves and the muscle each innervates:

Medial pectoral nerve

Answer 4

• Runs lateral to or through the pectoral minor muscle, actually lateral to the lateral pectoral nerve
• innervates the pectoral minor and pectoral major muscles

Question 5

Describe the location of these nerves and the muscle each innervates:

Lateral pectoral nerve

Answer 5

• Runs medial to the medial pectoral nerve
• innervates the pectoral major

Question 6

Identify the nerves in the axilla on the illustration below:

Answer 6

1. Thoracodorsal nerve
2. Long thoracic nerve
3. Medial pectoral nerve
4. Lateral pectoral nerve
5. Axillary vein

Question 7

What is the name of the deformity if you cut the long thoracic nerve in this area?

Answer 7

“Winged scapula”

Question 8

What is the name of the CUTANEOUS nerve that crosses the axilla in a transverse fashion? (Many surgeons try to preserve this nerve)

Answer 8

Intercostobrachial nerve

Question 9

What is the name of the large vein that marks the upper limit of the axilla?

Answer 9

Axillary vein

Question 10

What is the lymphatic drainage of the breast?

Answer 10

Lateral: axillary LNs

Medial: parasternal nodes that run with internal mammary artery

Question 11

What are the levels of axillary LNs?

Answer 11

Level I (low): lateral to pectoral minor

Level II (middle): deep to pectoral minor

Level III (high): medial to pectoral minor

In breast cancer, a higher level of involvement has a worse prognosis, but the level of involvement is less important than the number of positive nodes

Question 12

What are Rotter’s nodes?

Answer 12

Nodes between the pectoralis major and minor muscles; not usually removed unless they are enlarged or feel suspicious intraoperatively

Question 13

What are the suspensory breast ligaments called?

Answer 13

Cooper’s ligaments

Question 14

Which hormone is mainly responsible for breast milk production?

Answer 14

Prolactin