Anatomy of the breast

Question 1

What is the retromammary space?

Answer 1

potential space of loose subcutaneous tissue plane - allow some movement of the fascia

Question 2

Boundaries of the breast

Answer 2

overlies pectoralis major and minor
anchored to thoracic wall
lateral to sternum
mid axillary line
ribs 2-6

Question 3

Pre puberty breasts contents

Answer 3

(males + females)
fat
rudimentary duct system

Question 4

What happens to the breasts in puberty in females?

Answer 4

increase in oestrogen causes:
- expansion of duct system
- gland tissue forms

Question 5

What forms most of the bulk of the breast (except during lactation)?

Answer 5

fat

Question 6

What causes breast skin pitting?

Answer 6

‘orange peel skin’
Cooper’s ligaments may be contracted in cancer of the breast which produces pitting of overlying skin

Question 7

What do the lactiferous ducts drain?

Answer 7

each lactiferous duct drains one lobe of the mammary gland

Question 8

When does the areola darken?

Answer 8

during 2nd month of 1st pregnancy
permanent change

Question 9

Blood supply to the breast

Answer 9

arteries:
internal thoracic (perforating branches)
axillary (lateral thoracic and thoraco-acromial)
intercostals

veins:
- internal thoracic vein
- axillary vein
- intercostal veins

Question 10

What regulates milk production?

Answer 10

pituitary gland under autonomic control

Question 11

What are mammary (milk) lines?

Answer 11

in mammals, mammary glands and nipple development occur along 2 lines called milk lines which extend from the axilla to the inguinal region
these appear as faint ridges in the embryo formed from invagination of ectoderm (7 weeks)
ultimately, these in the thoracic region give rise to mammary buds then lactiferous ducts
other places the ridges disappear
this is also how accessory nipples and/or breast tissue occur - anywhere along milk line

Question 12

Female breast development stages

Answer 12

stage 1 = only tip of nipple is raised
stage 2 = buds appear, breast and nipple raised, and areola enlarges
stage 3 = breasts are slightly larger with glandular breast tissue present
stage 4 = areola and nipple become raised and form a 2nd mound above the rest of the breast
stage 5 = mature adult breast, breast becomes rounded and only the nipple is raised

Question 13

What helps prevent bacteria from entering lactiferous ducts in non-lactating women?

Answer 13

keratin ducts

Question 14

What happens to milk ducts at onset of menopause?

Answer 14

involution and shrinkage of milk ducts

Question 15

Where do majority of breast diseases originate from?

Answer 15

lactiferous ducts as high cell turnover

Question 16

What are the 4 quadrants of the breast?

Answer 16

upper outer (including axillary tail)
upper inner
lower inner
lower outer

Question 17

Lateral breast lymphatic drainage

Answer 17

5 groups of axillary nodes

Question 18

Superior breast lymphatic drainage

Answer 18

interpectoral nodes (Rotter’s nodes)

Question 19

Medial breast lymphatic drainage

Answer 19

parasternal nodes to thoracic ducts

Question 20

How can cancer in one breast spread to the other?

Answer 20

spread via parasternal nodes

Question 21

What are the 3 levels of surgical dissection relative to pec minor in breast cancer? (removes nodes in these regions and every region before)

Answer 21

level 1 = below (lateral to) pec minor
level 2 = deep to pec minor
level 3 = above (medial to) pec minor