Normal Anatomy of the Breast Flashcards
The breast is present in what form in males?
Rudimentary form
The breast is a site of malignant change in how many women?
1 in 10
What are the functions of the breast?
Secondary sexual feature in females
Source of nutrition for the neonate
What kind of glands are breasts developed from?
Modified and highly specialised sweat glands
What is the breasts special capsule or sheath?
It doesnt have one
Breast size and shape depends on?
Genetic, racial, and dietary factors
The breast extends vertically between which ribs?
2nd or 3rd rib to 6th rib
The breast extends transverselly from where to where?
Sternal edge to midaxillary line
What is the location of the axillary tail (of spence) or process?
A small part of the breast that extends towards the axillary fossa
What fascia does the breast lie on?
Deep pectoral fascia
2/3rd of the breast rests on the pectoral fascia covering pectoralis major
1/3rd of the breast rests on the fascia covering serratus anterior
What bursa (space) helps the breast with some degree of movement?
Retromammary space (bursa)
The breast is firmly attached to the dermis by what?
What does this help do?
Suspensory ligament of cooper
Help support the lobules of the gland
What is the nipple and areola?
Nipple - prominence of the breast
Areola - Pigmented area around the nipple
Each breast contains how many lobules of glandular tissue (parenchyma)?
15-20
Each lobule is drained by what?
Lactiferous duct
opens independently on the nipple
WHat is the dilated portion of each duct called?
Lactiferous sinus
Describe the nipple:
Whats its surface like? What is it made of? Whats its position?
No fat or hair
Conatins collagenous dense connective tissue, elastic fibres and bands of smooth muscle
Position: variable or 4th intercostal space
THe tips of nipples are fissured with what?
Lactiferous ducts opening into them
What is the structure and function of the areola?
Skin covering the nipple and areola contains numerous sweat and sebaceous glands
Oily material secreted by the sebaceous glands provides a protective lubricant for nipple and areola
What happens to the areola during pregnancy?
Enlarge
For anatomical location and description of pathology (cysts and tumours) the breast is divided into 4 quadrants
Name the 4 quadrants of the breast.
Superolateral quadrant
Superomedial quadrant
Inferolateral quadrant
Inferomedial quadrant
Which quadrant is the axillary tail a part of?
Extension of breast tissue in the superolateral quadrant
Describe the male breast
Rudimentary throughout life
formed by small ducts without lobules or alveoli
Little supporting fibroadipose tissue
Temporary enlargement in newborn and during puberty
During development of the breast mammary crests or ridges appear when?
During 4th week
The mammary crests or ridges extend from where to where during development?
Extend from axillary region to inguinal region
During breast development the crests usually disappear except in which region?
Pectoral region
How do the lactiferous ducts and their branches develop?
Primary mammary buds -> secondary buds -> lactiferous ducts and their branches
What is gynecomastia?
Postnatal development of rudimentary lactiferous ducts in males
During mid puberty about 2/3rd of boys develop varying degrees of hyperplasia of the breasts
What is polymastia?
An extra breast
What is polythelia?
An extra nipple
What athelia or amastia?
Absence of nipple or breast
What is the blood supply of the breast?
Supplied by branches of:
- Axillary artery
- Internal Thoracic artery
- Some intercostal arteries
Thoraco acromial artery
Lateral thoracic artery
Internal mammary (thoracic) artery
What nerves supply the breast and what do these convey?
Anterior and lateral cutaneous branches of 4-6th intercostal nerves
They convey sensory fibres to the skin of the breast
They also carry sympathetic fibres to the blood vessels and to the smooth muscle around the nipple
What is the clinical significance of the lymphatic drainage of the breast?
Metastatic dissemination occurs primarily by the lymphatic routes
Breast lymphatics branch extensively and do not contain valves
Most lymph (more than 75%) from the lateral quadrants drains where?
Axillary lymph nodes
Lymph from the medial quadrants of the breast drains where?
Parasternal or to opposite breast
Some lymph from the breast drains where?
Directly to supraclavicular or inferior cervical nodes
What is used to locate the sentinal node in breast cancer?
A radiolabelled colloid
At the time of surgery, a vital blue dye is injected
A combination of radioisotope and dye provides most accurate means of localising the node
The breast soft tissue is made of lobes which contain what?
Network of glandular tissue consisting of branching ducts and secretory lobules in a connective tissue stroma
What is the functional milk secretory component of the breast?
The terminal duct lobular unit
What is the difference between the connective tissue stroma that surrounds the lobules and the intralobular tissue?
The connective tissue stroma that surrounds the lobules is dense and fibrocollagenous, whereas intralobular tissue has a loose texture
Describe the histology of the normal breast
Extensive branching duct system
Surrounded by dense fibrous interlobular tissue and adipose tissue
Ducts and acini are lined by two layers of cells
- Luminal epithelial cells
- Myoepithelial cells
Describe the prepuberty breast
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
Describe the puberty breast
Branching of lactiferous ducts
Solid, spheroidal masses of granular polyhedral cells (alveoli)
Accumulation of lipids in the adipocytes
Describe the post menopausal breast
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 the lactating breast
Acini distended with milk
Thin septa between the lobules
At high magnification
-Acini with eosinophilic material containing clear vacuoles
Milk production
- Suckling
- Neurohormonal reflex
- Prolactin and oxytocin
What are the daignostic methods for the breast?
Imaging:
- Mammography
- Ultrasound
Fine needle spiration cytology
Core biopsy
What is the epidaemiology of breast cancer?
20% of all cancer in women
Commonest cause of death in women in 35-55 age group
In UK, any woman has a 1 in 9 chance of developing breast cancer
Name the 4 types of benign breast tumours
Fibroadenomas
Duct papillomas
Adenomas
Connective tissue tumours
What is Paget’s disease of the nipple?
Erosion of the nipple resembling eczema
Association with ductal or invasive carcinoma
