3s: Breast Pathology Flashcards
What is the triple test for breast conditions
C1-5 what is the gold-standard
structure of breast
- Clinical examination
- imaging = sonogrpahy, mammography, MRI (MRI only for small lesions missed by previous two)
- pathology
Cytopathology (FNA) = cells spread across slide and stains
- C1 = inadequate sample
- C2 = benign
- C3 = atypia
- C4 = suspicious of malignancy
- C5 = malignant
Histopathology (Core biopsy, GOLD-STANDARD) = intact tissue removed, normal is ductal-lobular system lined by inner glandular epithelium
Terminal duct lobular unit (TLDU)
- Stained purple is the breast’s glandular tissue
- Pink area around the glands is the stroma
- Large pink circle in the middle of the top left image is the duct with the acini around the duct
- This unit is called the terminal duct lobular unit (TDLU)
- Blue arrows are pointing towards myoepithelial cells (this helps to pump milk)
- Epithelial (luminal) cells are on the inside of myoepithelial cells
give 3 inflammatory breast diseases
Duct ectasia
Acute mastitis
Fat necrosis
Duct ectasia = inflammation and dilatation of large breast ducts, benign
- Aetiology unclear = multiparous, 40-60 yo women, smoking (BIGGEST RF)
- nipple discharge = thick, white nipple secretions
- breast pain, breast mass, nipple retraction
- can lead to mastitis, abscess, fistula
Cytology = proteinaceous material and neutrophils ONLY
Histology
- duct distension with proteinaceous material in it
- foamy macrophages
Acute mastitis = acute inflammation in breast
- often in lactating women due to cracked skin and milk stasis
- may complicate duct ecstasia
- organism = staphylococci (lactational)
- non-lactational = keratinising squamous metaplasia
- painful (tender), red breast
- mx = drainage and abx
- cytology = neutrophils
Fat necrosis = inflammatory reaction to damaged adipose tissue
- causes = trauma, surgery, radiotherapy
- breast mass
- cytology = fat cells surrounded by macrophages
Give 5 benign breast conditions
- Fibrocystic disease = group of alterations which reflect normal, albeit exaggerated, responses to hormonal influences
- Fibroadenoma = benign fibroepithelial neoplasm of breast
- Phyllodes (leaf-like) tumour = a group of potentially aggressive fibroepithelial neoplasms of the breast
- Intraductal papilloma = a benign papillary tumour arising within the duct system of the breast
- Radial scar = benign sclerosing lesion characterised by a central zone of scarring surrounded by a radiating zone of proliferating glandular tissue (mimics breast cancer on radiology
Fibrocystic disease – group of alterations which reflect normal, albeit exaggerated, responses to hormonal influences (e.g. menstrual cycle)
- Very common
- Presentation: breast lumps
- No increased risk for subsequent breast carcinoma
- Histology → ducts dilated; ducts calcified (seen on mammogram)
Fibroadenoma ‘breast mouse’ – benign fibroepithelial neoplasm of breast
- Common
- Presentation: well circumscribed mobile breast lump [young women; 20-30yo]
- Treatment: ‘shell out’
- Histology → glandular and stromal cells
Phyllodes (‘leaf-like’) tumour – a group of potentially aggressive fibroepithelial neoplasms of the breast
- UNCOMMON
- Presentation: enlarging mass in women >50 years
- Some may arise within pre-existing fibroadenomas
- Vast MAJORITY are BENIGN (but a small proportion can behave aggressively (malignant phyllodes))
-
Histology → overlapping cell layers, cellularity
- Level of malignancy determined on cellularity of the stroma
- High cellularity + stromal overgrowth → malignant
Intraductal papilloma – a benign papillary tumour arising within the duct system of the breast
Arises within the:
- Small terminal ductules (peripheral papilloma)
- Large lactiferous ductules (central papilloma)
COMMON (mainly in 40-60 years)
Central papillomas present with bloody nipple discharge
Peripheral papillomas may remain clinically silent
Treatment: excision of duct
Cytology = clusters of cells, potential increased risk with multiple papillomas of carcinoma
Histology = dilated ducts; polypoid mass in the middle
- Fibrovascular core (which nourished the polyp)
- Blood vessels within the stroma
Intraductal papilloma – a benign papillary tumour arising within the duct system of the breast
Arises within the:
- Small terminal ductules (peripheral papilloma)
- Large lactiferous ductules (central papilloma)
COMMON (mainly in 40-60 years)
Central papillomas present with bloody nipple discharge
Peripheral papillomas may remain clinically silent
Treatment: excision of duct
Cytology = clusters of cells, potential increased risk with multiple papillomas of carcinoma
Histology = dilated ducts; polypoid mass in the middle
- Fibrovascular core (which nourished the polyp)
- Blood vessels within the stroma
Radial scar – benign sclerosing lesion characterised by a central zone of scarring surrounded by a radiating zone of proliferating glandular tissue (mimics breast cancer on radiology)
- Range in size from microscopic to large / clinically apparent
- Lesions >1 cm = complex sclerosing lesions
- Thought to be due to exuberant reparative phenomenon in response to areas of tissue damage in the breast
- Presentation: stellate masses on screening mammograms (may closely resemble carcinoma)
- Excision is curative
-
Histology = two distinct areas:
- Central stellate area
- Peripheral proliferation of ducts and acini
what are proliferative breast diseases?
a diverse group of microscopic intraductal proliferative lesions of the breast associated with an increased risk of subsequent development of invasive breast carcinoma → produce no symptoms (found on biopsy)
Give 3 examples of proliferative breast diseases
(1) Usual epithelial hyperplasia [LEFT] – not a true pre-malignant change
- Marker of slightly increased risk of breast cancer
- The lumens are quite irregular (but this is a benign feature)
- glandular tissue and epithelial cell growth forming fronds
(2) Flat epithelial atypia/atypical ductal carcinoma [MIDDLE] – the first likely low-grade malignant change
- FEA may represent the earliest morphological precursor to low grade ductal carcinoma in situ
- 4 x increased risk of developing cancer
- There are multiple layers of epithelial cells and the lumens are becoming more regular
(3) In situ lobular neoplasia [RIGHT]
- Associated with an increased risk of invasive breast carcinoma
- It occurs within the acinar unit of the breast
- You get a very solid proliferation of cells within the acinus
Ductal Carcinoma in situ = neoplastic intraductal epithelial proliferation with risk of progression to breast cancer
- COMMON (Incidence has INCREASED since screening programmes came into effect)
- 85% are detected on mammography (areas of microcalcification)
- 10% will produce clinical features (lump, Paget’s disease); 5% diagnosed incidentally
DCIS histological classification: low, intermediate or high grade
LOW → cribriform/punched-out DCIS
- lumens compact/regular
- calcification (cells rapidly dying and regenerating)
- overlapping cells
HIGH
- central lumen necrotic material (large cells)
- pleomorphic cells occlude the duct (few limens)
How do we treat DCIS
- Treatment: surgical excision (chemotherapy is hardly ever given)
- Recurrence is more likely with high grade or extensive disease
Invasive breast carcinoma (the breast cancer you know)= a group of malignant epithelial tumours which infiltrate within the breast and have the capacity to spread to distant sites
RFs
- MOST COMMON cancer in women (1 in 8 risk); Incidence increases with age
Risk factors
- Early menarche
- Late menopause
- Obesity
- Alcohol
- OCP
- FHx (5% inheritance)
- Genetics → BRCA mutations (up to 85% increased lifetime risk)
TWO distinct genetic pathways for invasive carcinomas
Low Grade – arise from low grade DCIS or in situ lobular neoplasia and show 16q loss
High Grade – arise from high grade DCIS and show complex karyotypes with many unbalanced
4 types of invasive breast carcinoma
Invasive ductal carcinoma = pleiomorphic cells with large nuclei
- AKA: Non-specific type
- E-cadherin +ve
Invasive lobular carcinoma = linear (‘Indian File’ pattern), monomorphic (look similar)
Invasive tubular carcinoma [MIDDLE] = elongated tubules invading the stroma
Invasive mucinous carcinoma [RIGHT] = empty spaces contain lots of mucin
Two types of carcinoma in situ
What do we use to differentiate between invasive ductal carcinoma and invasive lobular carcinoma?
E-cadherin +ve = invasive ductal carcinoma
E-cadherin -ve = invasive lobular carcinoma
Basal-like carcinoma = carcinoma type discovered following genetic analysis of breast carcinomas
- Histology = sheets of markedly atypical cells, prominent lymphocytic infiltrate, central necrosis
- Immunohistochemistry = +ve for “basal” cytokeratins CK5/6 and CK14
- Associated with BRCA mutations
- Propensity to… vascular invasion and metastasis
