Breast Sanjaya Adikari Department of Anatomy. Consists of milk producing glands Consists of milk producing glands Glands are modified sweat glands Glands.

Breast

Sanjaya AdikariDepartment of Anatomy

Consists of milk producing glands

Glands are modified sweat glands

Assist reproduction in women

Rudimentary in men

Lies in the subcutaneous tissue

Extension transverse – LSB to MAL vertical – 2nd to 6th rib

Position of nipples 4th 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

retro-mammary space

pectoral fascia

posterior capsule

suspensory ligaments of Cooper

• Contains loose connective tissue

• Condensation of the membranous layer of superficial abdominal fascia of Scarpa

• Connects the dermis of the skin to the posterior capsule

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

15-25 15-25 breast lobes

of Cooper

Resting breastLobule

Alveolar ducts

Lined by cuboidal cells

Myoepithelial cells between the cuboidal cells and the BM

Cyclical changes according to the ovarian cycle

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

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

Thoracoacromialtrunk

Blood supply

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

axilla

inguinal region

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

Lymph drainage

75%

25%

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

Axillary lymph nodes

apical

central

anteriorposterior

lateral

Subclavian lymph trunk

Jugular lymph trunk

Right lymph duct

Flow of lymph from axillary nodes

Breast Quadrants

4 c

m

lump

Upper outer quadrant

Bulk of the tissues

most benign/malignantconditions occur in this quadrant

retro-mammary space

pectoral fasciaposterior capsule

suspensory ligaments of Cooper

dimpling

Mammogram

Tumour

Tension lines of the skin

Tension lines of the breast

surgicalincisions

Radial incision

Lactiferous ducts

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

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