Breast Flashcards
Describe the anatomy of the breast
The breast is a large sweat gland modified to produce milk (instead of sweat).
The female breast is made up of approximately 15-25 lobes - each composed of groups of lobules.
COOPER’S DROOPERS = cooper’s ligaments hold up the breast
The entire duct + lobular system is lined by epithelium surrounded by a basement membrane
What is the functional unit of the breast
The Terminal Duct Lobular Unit (TDLU)
Explain the production of milk
The lobule (TDLU) is composed of multiple acini (glands) and it is within the acini that the milk is produced. The milk drains via the terminal ducts into the main duct system of the breast - eventually opening out at the nipple where the baby suckles.
What is the most likely cause of a breast lump in a young woman
- Fibroadenoma
- Fibrocystic change
Cancer is much less common
What is the most likely cause of a breast lump in an older woman
- cancer is an important cause
- fibroadenoma
- fibrocystic changes
can both still occur
How would you investigate a breast lump
Triple assessment
What is triple assessment
- Clinical = history + examination
- Radiological = <35 years undergo ultrasound (breast tissue much denser) >35 years undergo mammogram (identifies micro calcifications and densities)
- Pathological - FNA / core biopsy
How do you interpret FNA/core biospy
C = FNA cytology; B = biopsy
C1/B1 = inadequate or not diagnostic C2/B2 = benign eg. fibroadenoma, fibrocystic change C3/B3 = equivocal, favour benign C4/B4 = equivocal, favour malignant C5/B5 = malignant - although this category also includes DCIS
What is a fibroadenoma
The commonest benign tumour of the breast.
Who gets fibroadenomas
Typically women under the age of 30
How does fibroadenoma present
Firm, mobile, painless lump.
May be multiple.
The tumour is well circumscribed and composed of well differentiated glands embedded in a well differentiated connective tissue stroma
How are fibroadenomas managed
Reassurance and discharge
Excision
What is fibrocystic change
A variety of benign, non-neoplastic changes in the breast which are the result of minor aberrations in the normal response to cyclical hormonal changes.
The changes affect the TDLU (functional unit of the breast) - which is characterised by fibrosis (scarring) and cyst formation
Who gets fibrocystic change
Typically seen in women 25 - 45
How does fibrocystic change present
- Breast pain
- Tenderness
- Lumps/cysts (“lumpy bumpy breasts”)
This is especially likely during the second half of the menstrual cycle
What is the management of fibrocystic change
Treatment options include: reassurance; analgesics; cyst aspiration; excision (rare)
What is the most common cancer in the UK
Breast cancer
Who gets breast cancer
Women (>99% of cases)
Rare before 25
Most common between 40 and 70 (80% diagnosed in >50yrs)
What are major risk factors for breast cancer
(1) Increasing lifetime oestrogen exposure
(2) FHx
(3) Alcohol consumption
What increases lifetime oestrogen exposure
(A) female sex (B) increasing age (C) obesity (fat makes oestrogen) (D) early menarche (E) late menopause (F) long term COCP (G) HRT > 10 years
What genes are associated with breast cancer
(A) BRCA1 + BRCA2 (TSGs; autosomal dominant; lifetime risk of breast cancer 85-100%; high risk of ovarian cancer; may be offered propylactic surgery)
(B) Li-Fraumeni syndrome - P53 germ line mutation
What is the most common site of breast cancer
Upper outer quadrant of the breast - as this is where there is the greatest proportion of breast parenchymal tissue
What features on examination make you suspect breast cancer
- Hard, painless lump (may be fixed to chest wall or overlying skin)
- Nipple inversion
- Skin dimpling
- Ulceration/fungation
- Peau d’orange - cutaneous oedema secondary to dermal lymphatic obstruction = the dimples are where the hair follicles are and the breast is swollen around them
- Nipple eczema (in pagets)
- Palpable auxiliary nodes - suggests tumour has spread here
- Metastatic disease (weight loss/pleural effusion)
How would you investigate breast cancer
Triple assessment
Grade - via biopsy
Stage
How is breast cancer managed
Discussed in an MDT meeting
- surgeon
- oncologist
- radiologist
- pathologist
- specialist nurse
Treatment plan is agreed - depends on tumour type, grade, stage, patient fitness, patient choice
What is the most common type of breast cancer
Invasive adenocarcinoma - the most common types are: Ductal carcinoma (75%) Lobular carcinoma (15%)
What is an adenocarcinoma
Malignant tumour of the glandular epithelium (the breast is a gland!)
What is DCIS
Ductal carcinoma in situ. This is where epithelial cells showing cytological signs of malignancy are present in the TDLU.
However, the basement membrane is intact - they have not invaded into the surrounded tissue.
- Pre-cancer
- Confined by BM
What is invasive ductal carcinoma
The tumour cells have invaded through the basement membrane into the adjacent fatty tissue. Invasive ductal carcinoma invades into adjacent breast tissue and it has the ability to metastasise.
What types of ductal carcinoma are malignant
IDC fulfils the two criteria for a malignant tumour - invasive with the ability to metastasise
DCIS has not invaded into the adjacent breast tissue - and it has not invaded through the BM therefore does not have the ability to metastasise. This is not malignant. However it should be noted that DCIS if left untreated can progress to IDC (DCIS = pre-cancerous).
How does DCIS present and what would you see on investigation
- Does not usually form a mass
- Often associated with micro calcifications - may be detected on mammography
- Usually a unifocal lesion concentrated in one area of the breast
How is DCIS treated
Unifocal and many progress to IDC so it is surgically excised.
How does IDC present
Palpable breast mass
What is Paget’s disease of the nipple
It affects the skin of the nipple and areola. It is due to the presence of DCIS cells in the epidermis (they extend all the way along the duct system to react the skin surface) - the affected skin “reacts” to the presence of the DCIS cells = characteristic eczematous clinical appearance
How is Paget’s disease of the nipple investigated
Biopsy
How is DCIS graded
FNA/biopsy will show it as C5/B5 - although it is not malignant
What is ILC
Tumour cells which infiltrate the normal breast tissue in a linear (single-file) pattern OR as single cells that appear to be separate
This is due to a loss of function of E-cadherin-catenin cell adhesion system
What is the most important prognostic factor in invasive breast cancer
Tumour stage (TNM) - particularly lymph node status
List prognostic factors in invasive breast cancer
(1) tumour stage - spread
(2) tumour grade - how differentiated and thereby aggressive
(3) Histological subtype
(4) Vascular invasion
(5) Excision margin
(6) Oestrogen receptor / HER2 status
Is is a good or bad prognostic factor to have a ER (oestrogen receptor) positive breast tumour?
Postive prognostic factor as they tend to be lower grade and less aggressive and are likely to respond to hormonal therapy.
What is the HER gene
An oncogene that encodes a transmembrane tyrosine kinase receptor.
HER2 over expression is associated with poor prognosis, however good response to perception (a monoclonal antibody against the HER2 receptor)
What is the setinel lymph node
The first lymph node draining a cancer
What is the clinical significance if the setinel lymph node does not contain cancer
There would be a very high likelihood of the cancer spreading to other nodes or elsewhere (since the cancer has to pass through the sentinel node first)
How is the setinel node used in determining management of breast cancer
Sentinel node +ve (contains cancer) = axiliary clearance - removal of all axilliary nodes
Sentinel node -ve (no cancer) = no further surgery in axilla is required
What are advantages of setinel node technique
- Important prognostic information
- Negative sentinel node are spared an unnecessary ax node clearance
How is the setinel node identified
- Dye and / or isotope injected into the tissue around the tumour
- Assess which lymph nodes that have taken up the dye
- Remove them
- Pathologist examines for signs of cancer
What is the NHS breast screening programme
Aim is to identify DCIS and small invasive carcinomas at early stage before S+Sx develop
Women 47-73 invited for a mammogram every 3 years
