(11.1+2) Breast and Lactation Flashcards
Describe the structure of the breasts.
- Blood vessels
- Fat & fibrous tissues
- Alveoli in lobules that secrete milk
- Lactiferous ducts that transport milk
- Myoepithelial cells that controls the let down of milk
Describe the anatomical position of the breasts.
- Lateral sternal angle - Mid-axillary line
- 2nd - 6th Rib
What milk is formed before it matures? Describe its constituents and how it differs from mature milk?
Colostrum Milk first week after birth
- Less: Water soluble vitamins (B & C) & Fat & Sugar
- More: Fat soluble vitamins & Proteins & Immunoglobin
- Fat & Sugar rise over the following 2-3 weeks
Describe the constituents in Mature Milk.
- 90% water
- 7% Lactate
- 2% Fat
- Vitamins
- Minerals
- Lactalbumin
- IgG
Describe how the milk let down is initiated.
Suction -> Hypothalamus -> Posterior Pituitary Gland -> dramatic decline in Oxytocin -> Myoepithelial cells contract
Describe the hormonal control of the growth & cessation of the breast tissues (starting from birth to old age).
(0) At birth: few Lobules
(1) Puberty (+ Oestrogen): Ducts sprouts and branch & Alveoli formation
(2) Menarche (+ Oestrogen): + number of Lobules & Stromal tissue
(3) Menstrual cycle
- Follicular phase: Lobules inactive
- Post-ovulation: Cells proliferation & Stromal oedema
- Menstruation: - Lobule size
(4) Pregnancy (Progesterone > Oestrogen):
- First 1/2 no lactation yet: Hypertrophy of Tubo-Lobule-Alveolar system & Stroma reduce
- Second 1/2: Differentiated Alveoli capable of milk production
(5) Birth giving (reduced Progesterone:Oestrogen ratio): responsiveness to Prolactin -> milk production
(5) Cessation (- Prolactin & - Turgor damages breast tissue): Atrophy of Lobules
(6) Ageing: Adipose tissue replace Stromal tissue
Describe the hormonal control of milk production.
Suction -> Hypothalamus -> reduced Dopamine & Vaso-active Intestinal peptide -> disinhibit Anterior Pituitary Gland -> Prolactin -> turgor & lactation
How do you normally investigate and diagnose breast pathology.
- Clinical: history & family history & examination
- Imaging: Mammogram & Ultrasound
- Pathology: Fine Needle Aspiration Cytology & Core Biopsy
List and describe briefly three inflammatory diseases of the breast.
- Mastitis: often Staphylococcus aureus enters via nipple crack/fissure (commonly secondary to breast feeding)
- Duct Ectasia: dilation & inflammation (mimic carcinoma clinically & mammographically)
- Fat Necrosis: masses (mimic carcinoma clinically & mammographically)
List and describe briefly three benign epithelial lesions of the breast.
- Epithelial hyperplasia: + cell number -> fill & distend ducts & lobules
- Fibrocystic changes: cysts formation (mimic carcinoma clinically & mammographically)
- Papilloma: finger-like projections outward
List and describe briefly two stromal tumours of the breast. At which age groups is each most commonly occur?
- Fibroadenoma often
List and describe briefly two developmental diseases of the breast (may include males).
- Polythelia: 3rd nipple, often appears in the embryonic milk line
- Gynaecomastia: breast development in males
List the risk factors of breast carcinoma.
- Exposure to Oestrogen e.g. female, pregnancy, long menarche-menopause interval
- Exogenous Oestrogen e.g. Hormone Replacement Therapy (but Oral Contraceptive Pills not much effect)
- Genetics: BRCA1 & BRCA2
- Ageing: often >50, but average diagnostic age is 64
- Radiation
- Fat diet & Obesity
- Breast feeding
Describe the classifications of breast carcinoma.
- Most commonly Adenocarcinoma
- In situ / Invasive
- Ductal / Lobules
Suggest ways and sites of metastasis of Invasive breast carcinoma.
- Blood streams
- Lymphatics / nodes (by the time of diagnosis, >50% of patients have Axillary node metastases)
- Lungs
- Bones
- Brain
- Liver
