Breast anatomy

Question 1

Describe the normal anatomy and histology of the breast.

Describe the lymphatic drainage of the breast and mode of lymphatic spread in breast disease.

Answer 1

.

Question 2

The breast extends from which ribs vertically

And transversely lies between what points

Answer 2

2nd - 6th

Sternal edge and mid-axillary line

Question 3

What small part of the breast extends towards the axillary fossa

Answer 3

Axillary tail of spence

Question 4

2/3 of the breast lies on what fascia

Other 1/3 lies on what fascia

Answer 4

Pectoral fascia covering pec major

Fascia covering serrates anterior

Question 5

The breasts are firmly attached to the dermis by what ligament

Answer 5

Suspensory ligament of Cooper

Question 6

Each breast contains 15-20 lobules

Each lobule is drained by a

Answer 6

lactiferous duct which opens on the nipple

Question 7

Each lactiferous duct has a dilated portion called the

Answer 7

lactiferous sinus

Question 8

Areola contains what

Answer 8

Sweat and sebaceous glands which secrete oily material that provides a protective lubricant for the nipple and areola

Question 9

Surface marking of the nipple

Answer 9

4th intercostal space (but varies)

Question 10

4 quadrants of the breast

• superolateral
• superomedial
• inferolateral
• inferomedial

Which quadrant does the axillary tail (extension of breast tissue) extend into

Answer 10

Superolateral

Question 11

Why are male breasts not prominent

Answer 11

Very little fat tissue

Question 12

Embryonic origin of breasts

Answer 12

Mammary crests/ridges appear in first 7 weeks which extend from axilla to inguinal region; the crests shorten over time and become recognisable in the thoracic region

Milk linesform as thickenings of theepidermisof the mammary ridge then nipples usually grow along the milk line

Question 13

What’s gynaecomastia + at what stage of life does it affect males

Answer 13

Enlarged breasts in males due to postnatal development of lactiferous ducts

Puberty and older men - usually due to imbalance in hormones (lower testosterone, higher oestrogen)

Question 14

Define

• polymastia
• polythelia
• athelia
• amastia

Answer 14

Extra breast
Extra nipple
Absence of nipple
Absence of breast

Question 15

Arterial supply to

• medial breast (1)
• lateral breast (4)

Answer 15

Internal thoracic - from subclavian

Lateral thoracic and thoracoacromial branches - from axillary

Lateral mammary branches - from post. intercostals

Mammary branch - from ant. intercostal

Question 16

The veins of the breast correspond with the arteries, draining into which 2 veins

Answer 16

Axillary and internal thoracic

Question 17

Innervation of breasts

Answer 17

anterior and lateral cutaneous branches of the 4th to 6th intercostal nerves (both SENSORY + AUTONOMIC)

Question 18

Lymphatic drainage of the breast (3)

Answer 18

Axillary nodes (75%) - drains lateral quadrant

Parasternal nodes - drains medial quadrant

Posterior intercostal nodes (5%)

Question 19

Mode of lymphatic spread in breast disease

Answer 19

Mostly to the axillary nodes then from there can spread to liver, lungs, bones, brain

Question 20

What is a sentinel lymph node + clinical significance

Answer 20

first lymph node to which cancer cells are most likely to spread from that primary tumour

Biopsy of the sentinel lymph node is carried out

Question 21

The soft tissue of the breast consists of lobes which is glandular tissue consisting of ducts and secretory lobules within a connective tissue stroma (separating it from other lobes)

The terminal duct lobular unit is what

Answer 21

functional milk secretory component of the breast

Question 22

Ducts and acini of the breasts are lined by 2 layers of cells - name these

Answer 22

Luminal epithelial and myoepithelial cells

Question 23

How does age change the development of the breast

• prepuberty
• puberty
• post-menopausal

Answer 23

Lactiferous ducts but no alveoli, little branching of the ducts, little fibrous storm and fat

Branching of lactiferous ducts, alveoli develop as solid spherical masses, lipids accumulate

Atrophy of lobules and ducts, fatty replacement of glandular tissue

Question 24

Changes in a breast during pregnancy on histology

Answer 24

Enlarged lobules
Dilated acini (large white blobs)

Question 25

Changes in a lactating breast on histology

Answer 25

Acini VERY DISTENDED with milk

Thin septa between lobules

Question 26

To assess a suspected breast cancer a triple assessment is carried out - what does this involve

Answer 26

Clinical examination

Imaging - mammogram and ultrasound scan

Biopsy

Question 27

Benign breast tumours

Answer 27

Fibroadenomas
Duct papillomas
Paget’s disease of the nipple