Repro - Breast Anatomy

Question 1

Where is milk made in the breast and how does it travel to the nipple?

Answer 1

Secretory lobes –> Lactiferous ducts –> Lactiferous sinuses –> Out nipple

All this is supported by fibro-fatty tissue

Question 2

What kind of gland is the breast tissue?

Answer 2

Highly specialized sweat glands

Question 3

What are the bony borders of the breast?

Answer 3

From 2/3rd rib to 6th vertically
From sternal edge to midaxillary line horizontally

There is also an Axillary tail to the breast that can stretch towards the axillary fossa

Question 4

What does the breast sit on?

Answer 4

2/3rd rest on Pectoral fascia (over pec major) & 1/3rd over fascia of serratus anterior

It also sits on the Retromammary bursa which enables some movement

Question 5

How is the breast attached to the skin?

Answer 5

Attached to the dermis by the Suspensory Ligament of Cooper

This supports the gland

Question 6

How many lobules of parenchyma are found in the breast?

Answer 6

15-20 in each breast

Question 7

What tissue type is the nipple?

Answer 7

Collagenous Dense CT
Elastic CT
Smooth muscle bands

(NO fat or hair on nipple)

Question 8

Where is the nipple in relation to bony landmarks?

Answer 8

Varys but ~ 4th intercostal space

Question 9

What is the function of the areola?

Answer 9

The skin over the nipple & areola contains lots of sweat & sebaceous glands, they enlarge in pregnancy and secrete an oily material that lubricates the nipple

Question 10

How do we divide up the breast when describing the location of pathologies e.g. cysts?

Answer 10

4 Quadrants:

• Inferomedial
• Inferolateral
• Superolateral (+axilaly tail)
• Superomedial

Question 11

Men have breasts too, how are they different?

Answer 11

• Undeveloped
• Small ducts but no lobules or alveoli
• Less Fibro-fatty tissue

Question 12

When do breasts start developing in the embryo?

Answer 12

Wk4 is when the mamary crests or ridges appear

Question 13

Where are the mammary crests found?

Answer 13

They extend from axillary to inguinal regions in the embryo, they eventually dissapear except in the pectoral region

Question 14

How does the mammary crest become a breast?

Answer 14

Most of the mammary crest dissapears leaving the:

• Pectoral part
• -> Primary Mammary Bud
• -> Secondary Mammary Bud
• -> Lactiferous ducts

The ducts then branch inwards until the form glands

Question 15

List some major embryological defects of the breast:

Answer 15

Polymastia (extra breast)
Polythelia (Extra nipple)
Atelia or Amastia (absence of nipple or breast)

Question 16

Define Gynaecomastia?

Answer 16

Postnatal development of lactiferous ducts in males

2/3rds of boys in puberty have hyperplasia of breast, not the same thing.

Question 17

What arteries supply the breast?

Answer 17

Thoraco Acromial Artery
Lateral thoracic artery (From axillary)
Internal thoracic artery

Question 18

What nerves innervate the breast and what do they do?

Answer 18

Anterior & Lateral cutaneous branches of 4-6th intercostal nerves:

• Sensory to skin of breast
• Symp to blood vessels
• Symp to smooth muscle of nipple

Question 19

Where does lymph drain in the breast?

Answer 19

Lateral quadrants:

• Mostly to Axillary Nodes
• Some to Supraclavicular or Inf Cervical nodes

Medial Quadrants:

• Parasternal nodes
• Other breast

Question 20

What is sentinal node biopsy?

Answer 20

When we find a cancer in the breast and remove it we also biopsy the first lymph node (found by injecting radioisotope dye) to assess for spread

Question 21

What cell types can you see on histology of breast tissue?

Answer 21

Ducts & Acini contain 2 cell types:

• Luminal epithelial cells
• Myoepithelial cells outside

Surrounded by Dense Fibrous Interlobular tissue (Stroma) and Adipose tissue

Question 22

What happens to the breast pre-puberty?

Answer 22

Some enlargement due to growth of fibrous stroma and fat

But not yet any lobules (ducts havent brancehd much)

Question 23

What happens to the breast during puberty?

Answer 23

Branching of lactiferous ducts and formation of alveoli

Lipids also accumulate in adipocytes

Question 24

What happens to the breast after menopause?

Answer 24

Progressive atrophy of the lobules & ducts

The glandular tissue is replaced with fat

Question 25

How does the breast change during pregnancy? (hist)

Answer 25

Lobules enlarge and acini dilate

The epithelium varies from cuboidal to columnar

Question 26

What is colostrum?

Answer 26

PRotein rich fluid full of maternal antibodies thats secreted a few days after birth

Question 27

How does the breast tissue appear during lactation (hist)?

Answer 27

Acini become distended with milk and the septa look very thin. At a high magnification you can see the acini contain eosinophilic material and clear vacuoles

Question 28

What hormones are released during suckling to stimulate milk production?

Answer 28

Prolactin & OXytocin

Question 29

How can you diagnose breast pathology?

Answer 29

Mammography & US
Fine Needle Aspiration Cytology
Core Biopsy

Go look at Powerpoint for images of mammography, will be in exam

Question 30

How might you see a carcinoma of the breast from the outside?

Answer 30

• Skin dimpling
• Abnormal contours
• Oedema of the skin (Peau d’orange sign)
• Nipple retraction / deviation

Question 31

List some benign tumours of the breast?

Answer 31

Fibroadenoma
Duct PApilloma
Adenoma
CT tumours

Question 32

What is Paget’s disease of the niple?

Answer 32

Erosion of the nipply that resembes eczema, commonly associated with ductal or invasive carcinoma