Normal Anatomy of the Breast Flashcards
breast margins
2nd - 6th rib sternal edge midaxillary line lies on deep pectoral fascia tail towards axillary fossa
what attaches the breast to the dermis?
suspensory ligament of cooper
how many lobules does each breast contain?
15-20
what drains the breast lobules?
lactiferous duct
describe the nipple
- No fat or hair
- Contains collagenous dense connective tissue, elastic fibres and bands of smooth muscle
- The tips of the nipples are fissured with lactiferous ducts opening into them
- Position : variable or 4th intercostal space
describe the areola
- Skin covering the nipple and areola contains numerous sweat & sebaceous glands
- Enlarge during pregnancy
- Oily material secreted by the sebaceous gland provides a protective lubricant for nipple and areola
describe the male breast
- Rudimentary throughout life
- Formed by small ducts without lobules or alveoli
- Little supporting fibroadipose tissue
- Temporary enlargement in newborn & during puberty
describe the development of the breast
- Mammary crests or ridges appear during 4th week
- These crests extend from axillary region to inguinal region
- The crests usually disappear except in the pectoral region
- Primary mammary buds – Secondary buds – lactiferous ducts and their branches
what is polymastia
an extra breast
what is polythelia
an extra nipple
what is athelia or amastia
absence of nipple or breast
blood supply to the breast
axillary artery
internal thoracic
intercostal
nerve supply to the breast
- Anterior and lateral cutaneous branches of 4- 6th intercostal nerves
- They convey sensory fibers to the skin of the breast
- They also carry sympathetic fibres to the blood vessels and to the smooth muscle around the nipple
breast lymphatic drainage
Most lymph (more than 75%) from lateral quadrants – axillary lymph nodes
• Some lymph may drain directly to supraclavicular or inferior cervical nodes
• Lymph from medial quadrants – parasternal or to opposite breast
role of the sentinel lymph node in breast cancer
- Lymphatic mapping & staging of patients
- A radiolabelled colloid is used to locate the sentinel node
- At the time of surgery, a vital blue dye is injected
- Combination of rodioisotope and dye provides most accurate means of localizing the node
describe the histology of the normal breast
Extensive branching duct system
• Surrounded by dense fibrous interlobular tissue (F) & adipose tissue (A)
• Ducts & acini are lined by two layers of cells – Luminal epithelial cells (E) & myoepithelial cells (M)
prepubertal breast changes
- Neonatal breast contain lactiferous ducts but no alveoli
- Until puberty, little branching of the ducts occurs
- Slight breast enlargement reflects the growth of fibrous stroma and fat
pubertal breast changes
- Branching of lactiferous ducts
- Solid, spheroidal masses of granular polyhedral cells (alveoli)
- Accumulation of lipids in the adipocytes
post menopausal breast changes
- Progressive atrophy of lobules and ducts
* Fatty replacement of glandular tissue
describe the histology of the breast during pregnancy
• Enlarged lobules
• Acini are dilated
• Epithelium vary from cuboidal
to low columnar
what is colostrum?
Protein rich fluid, available few days after birth – rich in maternal
antibodies
describe the histology of a lactating breast
- Acini distended with milk
- Thin septa (S) between the lobules
- At higher magnification (b) – Acini with eosinophilic material containing clear vacuoles
- Milk production – Suckling -Neurohormonal reflex –Prolactin & Oxytocin
name some benign breast tumours
- Fibroadenomas
- Duct papillomas
- Adenomas
- Connective tissue tumours
what is Paget’s disease of the nipple?
- Erosion of the nipple resembling eczema
* Associated with ductal or invasive carcinoma
