W3: Breast

Question 1

What type of gland?

Answer 1

Exocine

Question 2

What are they composed of?

Answer 2

Adipose and glandular tissue

Question 3

What do they lie over?

Answer 3

Pec major

Question 4

Discuss lobules

Answer 4

14-18 lactiferous lobules radially
around the nipple -> drain into
lactiferous ducts, which converge
at the nipple-areola complex.

Question 5

Areolar glands

Answer 5

Areolar glands: secrete an oily
substance onto the areola and
nipple to keep them protected and
lubricated

Question 6

Vasculature of rest

Answer 6

Medially → intercostal branches of internal thoracic
Laterally → axillary artery
Venous drainage follows this pattern

Question 7

Lymphatic drainage of breast

Answer 7

⚫75% of breast lymph drains into the
axillary lymph nodes
.
⚫Medially:
⚫parasternal lymph nodes
(within the intercostalspaces
(within the intercostalspaces
surrounding internal thoracic
artery (internal thoracic nodes)
⚫infraclavicular nodes
⚫abdominal wall nodes
⚫contralateral lymph nodes.

⚫Axillary tail lymph lymph nodes
peri-subscapular artery

Question 8

Sentinel lymph node biopsy

Answer 8

radioactive substance injected
peri-tumor to identify the first draining lymph node.

Question 9

Which ribs do breass extend over?

Answer 9

2nd and 6th

Question 10

axillary tail

Answer 10

The superolateral part of the breast, called the axillary tail, extends upwards and outwards into the axilla.

Question 11

Discuss ligaments

Answer 11

The tissue of the breast is supported by the suspensory ligaments, which pass between the deep fascia overlying pectoralis major to the dermis of the skin.

Question 12

Blood supply

Answer 12

The breast is supplied by the intercostal branches of the internal thoracic artery medially and branches from the axillary artery laterally. Venous drainage follows this arterial pattern.

Question 13

Lymphatic drainage

Answer 13

The lymphatic drainage of the breast is extremely important to appreciate due to the prevalence of breast cancer. 75% of breast lymph passes to the axillary lymph node groups surrounding the lateral part of pectoralis minor. Remaining lymph, predominantly from the medial breast, passes to the parasternal lymph nodes with- in the intercostal spaces, which surround the internal thoracic artery, as well as to the infraclavicular nodes, abdominal wall nodes or nodes on the opposite side of the chest. Lymph within the axillary tail of the breast typically drains to the lymph nodes around the subscapular artery.

Question 14

Breast cancer

Answer 14

Approximately 1 in 8 women (and 1 in 870 men) will be diagnosed with breast cancer in their lifetime. Risk factors include family history, older age, early menarche, late menopause and late first pregnancy. Most patients present with an asymptomatic breast lump found during self-examination or screening mammography. Breast cancers may be classified as carcinomas in situ, which do not have stromal tissue invasion, and invasive carcinomas. Breast cancer typically spreads through the region lymph nodes and bloodstream. In order to stage the breast cancer, the lymph nodes draining the breast cancer should be physically examined and biopsied. This may be performed using a sentinel lymph node biopsy, where dye and a radioactive substance are injected into the breast tissue to identify the first draining lymph node, or through axillary node dissection. Treatment of breast cancer includes surgical resection (mastectomy or breast conserving), radiotherapy and adjuvant systemic therapy.