Normal breast anatomy Flashcards
How are breasts present in males?
rudimentary form
What are the breasts?
highly modified sweat glands which are a 2nd sexual characteristic of females
What factors affect breast size?
genetic, racial and diet
axillary tail
part of breast extending towards axillary fossa
What fascia does the breast lie on?
deep pectoral
Function of rectomammary space
some degree of movement
What attaches breast to dermis
suspensory ligament of cooper
nipple
prominence of breast
areola
pigmented area around the nipple
How many lobules does each breast contain?
15-20
What drains each lobule?
lactiferous duct
Where do the lactiferous ducts open?
independently on the nipple
Dilated portion of lactiferous duct
lactiferous sinus
surface landmark of nipple
variable - 4th intercostal space
Role of sebaceous glands in nipple and areola epithelium
protective lubricant
4 quadrants of breast
superolateral and superomedial
inferolateral and inferomedial
Use of quadrants of breast
describing pathology
Mammary crests
appear in week 4 and extend from axilla to inguinal region
Where do the mammary crests not disappear from?
pectoral region
polymastia/amastia
extra/absent breast
amastia/athelia
extra/absent nipple
3 arteries to breast
thoraco-acromial
internal thoracic
lateral thoracic
Sensory innervation of skin of breast
anterior and lateral cutaneous branches of 4th-6th intercostal nerves
What do the nerves for sensory innervation of breast also carry?
sympathetic fibres to blood vessels and smooth muscle around nipple
Describe the lymphatics of the breast
main spread for mets
highly branched and no valves
Lymph from lateral part of breast drains to…
AXILLARY
can go straight to supraclavicular or inferior cervical
lymph from medial quadrants drain..
parasternal or opposite breast
sentinel node biopsy
radioisotope and dye injected to trace the 1st draining LN
2 cells which line ducts and acini
myoepithelial
luminal epithelial
Pre-puberty changes of the breast
lactiferous ducts but no alveoli - fat,
little branching of ducts
Puberty changes in breast
lactiferous ducts branching
solid, spheroidal masses of alveoli
lipids accumulate in adipocytes
post-menopausal changes in the breast
progressive atrophy of lobules and ducts
fatty replacement of glandular tissue
colostrum
protein rich fluid, available few days birth - rich in maternal ab
Breast changes in pregnancy
enlarged lobules
acini dilated
epithelium vary from cuboidal to low columnar
Lactating breast histology
acini dilated with milk
thin septa between lobules
milk production
Imaging breast
USS, mammogram
2 diagnostic methods of the breast
FNAC, core biopsy
Epidemiology of breast cancer
20% of all cancers in women, 1 in 8 risk
commonest cause of death in women 35-55
Symptoms of breast cancer
skin dimpling abnormal contours oedema nipple retraction lump orange peel skin
Benign breast tumours
fibroadenoma
cysts
connective tissue tumours
adenoma
Pagets
erosion of nipple resembling eczema
Ductal or invasive carcinoma association
