1. Breast
Sanjaya Adikari
Department of Anatomy

2. Consists of milk producing glands
Glands are modified sweat glands
Assist reproduction in women
Rudimentary in men
Lies in the subcutaneous tissue

4. Extension transverse – LSB to MAL
vertical – 2nd to 6th rib
Position of nipples th ICS in males
10 cm from AML
Size is variable due to the amount of fat surrounding the glandular tissue.
Extent of the base is fairly constant

7. suspensory ligaments of Cooper retro-mammary space posterior capsule
Connects the dermis of the skin to the posterior capsule
retro-mammary space
Contains loose connective tissue
posterior capsule
Condensation of the membranous layer of superficial abdominal fascia of Scarpa
pectoral fascia

8. Structure 15 – 25 lobes Each lobe drains by its lactiferous duct
Lobes consist of many lobules
Lobules consist of alveolar ducts
Lobules are separated by loose connective tissure
Lobes are separated by dense connective tissue

9. of Cooper
15-25 breast lobes
15-25

10. Smooth muscles

11. Resting breast Lobule Alveolar ducts Lined by cuboidal cells
Myoepithelial cells between the cuboidal cells and the BM
Cyclical changes according to the ovarian cycle

12. Breast during pregnancy
Changes due to oestrogen, progesteron, prolactin etc.
Numerous secretory alveoli formed by proliferating alveolar duct epithelium
Interlobular connective tissue becomes less
Alveoli and ducts get filled with Colostrum
Colostrum is a protein-rich fluid containing maternal antibodies
Breast during pregnancy

13. Lactating breast Consists entirely of glandular tissue
Alveoli are dilated with milk
Interlobular connective tissue disappears
Prolactin promotes the production of milk
Oxytocin causes contraction of myoepithelial cells and ejection of milk
Lactating breast

14. Blood supply
Thoracoacromial
trunk

16. Development of breasts
Mammary line or ridge develops at 7 weeks IUL
Thickening of epidermis
Persists only in thoracic region
If persists in other regions cause accessory nipples – common in axillary region
Epithelial sprouts formed and canalized

17. axilla
inguinal region

18. Development ….cont. Lactiferous ducts open into an ‘epithelial pit’
After birth the nipple is formed by proliferation of underlying mesenchyme
Persistance of epithelial pit causes inverted nipples.
An underlying tumour can also cause nipples to invert
Lobule formation occurs only in the female after puberty

19. Lymph drainage
75%
25%

20. Lymph drainage About 75% passes to axillary nodes
Rest of it mainly passes to parasternal nodes
Superficial lymphatics of the breast have connections with the opposite breast

21. Axillary lymph nodes
apical
lateral
anterior
posterior
central

22. Flow of lymph from axillary nodes
Jugular lymph trunk
Subclavian lymph trunk
Right lymph duct

24. Breast Quadrants lump Upper outer quadrant Bulk of the tissues 4 cm
most benign/malignant
conditions occur in this
quadrant

25. suspensory ligaments
of Cooper
dimpling
retro-mammary space
posterior capsule
pectoral fascia

26. Mammogram
Tumour

27. Tension lines of the skin

28. Tension lines of the breast
surgical
incisions
Lactiferous ducts
Radial incision

29. Mastectomy Radical mastectomy Modified radical mastectomy
whole breast, pec. Major & minor,
axillary fat,fascia & LNs
preserve pec. Major
but remove pec. minor
only the breast
breast with axillary tissue
Radical mastectomy
Modified radical mastectomy
Simple mastectomy
Extended simple mastectomy

30. Sentinel node/s First node/s to spread of a malignancy
Radioisotope labeled method
Blue dye injected around the tumour
These are assessed during surgery
Removed if tumour cells are detected