breast

Question 1

what are Tanner Stages?

Answer 1

Stage 1

(Puberty)

• Elevation nipple
• No palpable glandular tissue
• No areolar pigmentation

Stage 2

(11 +/- 1y)

• Subareolar glandular tissue is present
• Nipple & breast project as single mound

Stage 3

(12 +/- 1y)

• Increase in palpable glandular tissue
• Enlargement of breast, diameter & pigmentation of areola
• Contour of breast & nipple in same plane

Stage 4

(13 +/- 1y)

• Enlargement of areola, ↑pigmentation
• Nipple & areola form a 2^nd mound above level of breast

Stage 5

(15 +/- 2y)

• Final adult size
• Areola returns to the contour of the surrounding breast

Question 2

describe the borders of the breast.

Answer 2

• from 2nd to 6th rib (6th rib is IMF)
• from lateral sternal border to anterior axillary line

Question 3

what is the IMF

Answer 3

fusion of deep and superficial breast fascia with the dermis.

Question 4

describe cells of gland, lactiferous ducts, lactiferous sinus, nipple/areola

Answer 4

• gland - columnar
• duct - cuboidal
• sinus - squamous
• NAC - keratinized stratified squamous

Question 5

anatomy of breast structures

Answer 5

• there are millions of lactiferous ducts that form glands
• glands group to form 15-25 lobes
• each lobe has a lactiferous duct
• lactiferous duct dilate and coalesce to form lactiferous sinus that collects milk
• the milk ducts open as Montgomery glands, and around the periphery of areola they are raised and referred to as Morgagni’s tubercles

Question 6

describe fascia supports of breast

Answer 6

• breast is encased in a fascia sling
• the fascia is from scarpa’s superficial fascia, which splits into a superficial layer and deep layer
• the superficial layer is the superficial fascia of breast, dividing subcutaneous fat from breast tissue
• the deep layer rests above pec fascia, with an intervening loose areolar plane
• coopers ligaments run from deep layer of superficial fascia to superficial layer and dermis, suspend breaset tissue on chest wall; attenuation contributes to ptosis

Question 7

describe blood supply to breast

Answer 7

• breast has superficial and deep blood supply from 3 primary and 2 secondary sources
• primary
  
  • perforators 2-4 of IMA
  • lateral thoracic artery
  • anterior and lateral branchs of 3-5 intercostal arteries
• secondary
  
  • thoracoacromial
  • thoracodorsal
• deep
  
  • 4th IMA perforator sends a deep (transmuscular) branch; supplies inferior pedicle
• superficial
  
  • remaining blood supply is subdermal
• NAC receives blood supply from all sources, both subdermal and deep

Question 8

what are axillary LN levels?

Answer 8

• I – nodes lateral to/below lower border of pectoralis minor (lateral thoracic, axillary vein, and scapular groups)
• II – nodes deep to or behind pectoralis minor (central group)
• III – nodes medial to or above upper border or pectoralis minor (subcalvicular group)

Question 9

describe innervation to breast and NAC

Answer 9

• anteromedial and anterolateral branches of intercostal nerves T3-6
  
  • NAC is lateral branch of T4, both superficial and deep (through Wuringer’s septum)
• superior breast also innervated by superclavicular nerve from C3,4 cervical plexus
• intercostobrachial crosses axilla to upper arm / superolateral breast/tail

Question 10

What is the embryology of breast development

Answer 10

• breast parenchyma from ectoderm; surrounding connective tissue and stroma from mesoderm
• 5 wks: ectodermal milk streak forms mammary ridge from axillay to groin; mammary ridge regresses except paired pectoral buds remain
• 7-8 wks: invagination of mammary ectoderm into underlying mesenchyme
• 12-16 wks: ectodermal epithelial buds begin to branch; mesenchyme begins to differentiate, including into smooth muscle of areola
• 20 wks: 2’ mammary anlage forms, including adnexal structures and breast gland; fascial system begins to develop
• then placental hormone dependent development ensues
  
  • by week 20+ canalization of branching bud system ensues
  • by week 32-40 there is further parenchymal differentiation including opening of lactiferous ducts; areola becomes pigmented
    *

Question 11

list ideal features of a female breast shape

Answer 11

• Upper pole : lower pole of 45:55
• Nipple angulation slightly upwards at 20’
• Linear or slight concavity to upper pole
• Tight convex lower pole
• [symmetric in size and shape]