Breast Flashcards
What are good immuno markers for metastatic triple-negative breast carcinoma?
GATA3: stains 40% of TNBCs; 90% of breast cancers
SOX10: stains 60% of TNBC
Is HER2 used in identification of breast metastasis? why or why not?
No. Also stains esophagus/stomach, lung, GYN.
Name 4 myoepithelial markers used in breast.
SMA
Calponin
p63/p40
Smooth muscle myosin heavy chain
What benign lesion in the breast lacks myoepithelial cells (false negative)?
What stain do you use to rule it out?
Microglandular adenosis
S100 + to rule out breast cancer
Myofibroblasts can lead to false positive staining with which two stains?
SMA
Calponin
but will be p63-
What is the usual immunoprofile of breast cancer in general (Quick Reference)
CK7+
CK20-
GATA3+ (90%) ER/PR (60-70%) GCDFP Mammaglobin HER2 (10-30%)
what stains are used for lobular Ca?
ER/PR +
HER2 -
E-Cad (loss)
GCDFP15 (~100%)
p120
What is the immunoprofile of metaplastic breast carcinoma?
HMWCK: CK5/6, 34BE12
p63/p40+
variable AE1/AE3
SOX10
what are some histologic features of the nuclei in UDH?
Oval normochromatic \+/- grooves overlapping small, single, indistinct nucleoli scant or no mitoses
what are some histologic features of the architecture in UDH?
'streaming' effect peripheral elongated clefts no polarization around clefts tufts and mounds projecting into lumen bridges: irregular, not sharp; oval nuclei streaming in parallel across bridges.
other aspects: apocrine metaplasia peripheral myoepithelial cells presence of foamy macrophages necrosis uncommon
What is the immunoprofile of UDH?
CK5/6 MOSAIC (ADH and DCIS are negative for HMWCKs)
ER: heterogeneous (vs. diffuse strong nuclear in ADH and DCIS)
how goes ADH stain for HMWK and ER?
HMWCK: negative
ER: strong nuclear
What is the relative risk of subsequent breast cancer in women with ADH on a core biopsy?
4-5x risk
management is surgical excision
What is the relative risk of subsequent breast cancer in women with DCIS or LCIS on a core biopsy?
8-10x risk
What is ADH & what are the usual criteria to differentiate it from DCIS?
Atypical Ductal Hyperplasia
Has cytologic and architectural features of low-grade DCIS, BUT only partially involves the TDLU; OR, if it involves the whole TDLU, then it is <2mm or only present in fewer than two adjacent spaces.
Two or more spaces or >2mm = DCIS
What is the difference between ALH and LCIS?
ALH: <50% of the TDLU expanded
LCIS: >50% exapanded by atypical cells.
What 6 categories of criteria are used to distinguish benign from malignant phyllodes?
Tumor border Stromal Cellularity Stromal Atypia Mitotic Activity Stromal Overgrowth Malignant heterologous elements
(source: Table 3.01 WHO, Breast)
What are the criteria for mitotic rate used to distinguish benign & borderline from malignant phyllodes?
Benign: <5/10hpf
Borderline: frequent 5-9/10hpf
Malignant: abundant, >10/10hpf
What is the significance of stromal overgrowth & how is it defined?
Absent in Fibroadenoma and benign phyllodes; Absent/focal in borderline
Often present in malignant
Stromal overgrowth: defined by the absence of epithelial elements in one low-power microscopic field (40× magnification: 4× objective and 10× eyepiece) containing only stroma.
What criteria must be present for a diagnosis of malignant phyllodes?
marked stromal nuclear pleomorphism
stromal overgrowth
increased stromal cellularity (usually diffuse)
infiltrative border
Presence of malignant heterologous elements trumps all other criteria.
(Source: WHO, “Phyllodes.”)
What is the immunoprofile of phyllodes tumor?
CD34+
bcl2 (good to distinguish from metaplastic Ca)
ER beta and PR +
CD117 in 1/3
Rosai p. 1451
What is the prognosis of malignant phyllodes?
Risk of metastasis 3 - 12%
Local recurrence more common
axillary node mets exceptional/rare
Distant involvement rare; bone and lung
tx: wide local excision with adequate margin.
NB: only STROMA metastasizes
What is the main (important) differential diagnosis with malignant phyllodes?
Spindle cell metaplastic carcinoma
What is the immunoprofile of microglandular adenosis?
ER/PR-
S100+
What benign breast lesion lacks myoepithelial cells?
Microglandular adenosis
Define mammary Paget disease
Crusted lesion of the nipple caused by breast carcinoma in the nipple epithelium, accompanied (>95%) by an underlying breast carcinoma (typically high-grade DCIS).
Management depends on underlying cancer.
What is the immunoprofile of mammary Paget disease?
Positive: LMWCK (Cam5.2, CK7,) EMA, Her2 (70-100%) Mucicarmine (40-70%) GCDFP-15 (~50%)
Negative:
Melanocytic markers, S100
HMWCK (p63, p40)
What is the ddx of mammary Paget?
Melanoma in situ: negative for keratins, positive for melanocytic markers
Squamous cell carcinoma in situ:
Positive for HMWCK only (p63/p40)
negative for LMWCK, HER2, GCDFP15, melanocytic markers.
Name some risk factors for breast carcinoma.
Family history: 2-3x risk if first-degree relative.
Esotrogen exposure - menstrual/reproductive history: early menarche, nulliparity, late age at first birth, late menopause.
Intraductal proliferative lesions (1.5-2x); proliferative with atypia 4-5x
Exogenous estrogens
DCIS, LCIS 10x
alcohol intake
What is the function of BRCA genes
Repair of DNA double-strand breaks through homologous recombination.
What are the 3 elements of Nottingham grading?
Tubules; Mitoses; Nuclear Pleormorphism
What are the criteria for the Tubular grading in the Nottingham grading system?
Score 1-3
1: >75% tubules
2: 10 - 75% tubules
3. <10% tubules
How is microinvasion graded?
It is not graded!
What are the criteria for grading nuclear pleomorphism in breast cancer?
Score 1: small nuclei, comparable to normal
Score 2: larger, visible nucleoli, moderate variablity in size and shape.
Score 3: vesicular, prominent ncueloli, marked variation in size and shape, occasionally large and bizarre forms.
What are the criteria for grading mitoses in breast carcinoma?
Depends on the field diameter (see table in CAP)
Count is per 10 consecutive hpfs.
On a 0.55mm field diameter, this works out to:
score 1: <8
score 2: 9 - 17
score 3: 18 or more.
How is the overall grade determined for breast carcinoma?
Addition of scores from T, N, and M
Grade 1: score 3, 4, or 5
Grade 2: score 6-7
Grade 3: 8-9
Define macro and micrometastases, and isolated tumor cells:
Macrometastases: >2mm
Micrometastases: >0.2mm to 2mm and/or >200 cells
ITCs: less than 0.2mm or 200 or fewer cells
For breast carcinoma, define : pT1 pT2 pT3 pT4 (main categories only, not subclassification a, b, c etc)
pT1: Tumor 20mm or less
pT2: more than 20mm to 50mm
pT3: more than 50mm
pT4: any size
direct extension into the chest wall and/or to the skin (ulceration or skin nodules)
Define macro and micrometastases, and isolated tumor cells:
Macrometastases: >2mm
Micrometastases: >0.2mm to 2mm and/or >200 cells
ITCs: less than 0.2mm or 200 or fewer cells
What is inflammatory carcinoma and how does it alter the T stage?
Inflammatory carcinoma = tumor in dermal lymphatic spaces
Defined CLINICALLY by erythema and edema involving at least 1/3 of the skin of the breast.
stage: pT4d
What is the significance of ulceration of the skin that does not meet the criteria for pT4d inflammatory carcinoma?
Ulceration of the skin that does not meet criteria for pT4d is pT4b
Other pT4b: ipsilateral macroscopic satellite nodules and/or edema (including peau d’orange)
What is the significance of ulceration of the skin that does not meet the criteria for pT4d inflammatory carcinoma?
Ulceration of the skin that does not meet criteria for pT4d is pT4b
Other pT4b: ipsilateral macroscopic satellite nodules and/or edema (including peau d’orange)
What defines pT4a?
Extension to the chest wall
Does NOT include adherence to pectoralis major in absence of invasion of other chest wall structures.
How does invasion of the dermis alter T-staging?
It does not. Invasion of the dermis alone does not quality as pT4.
How do isolated tumor cells change the N stage?
They are still N zero but are reported: pN0 (i+)
Recall: ITCs = small clusters of cells not greater than 0.2mm or single tumor cells, or a cluster of fewer than 200 cells in a single section.
Name some typically ER-negative histologic types of breast carcinomas
Adenoid Cystic
Secretory
Medullary
Metaplastic
Apocrine
Triple negative - usually higher grade in general.
What is the translocation associated with adenoid cystic carcinoma of the breast?
t (6;9) MYB-NFIB
NB: MYB immunohistochemistry available
Adenoid cystic are triple negative
Good prognosis
What are the three principal non-proliferative morphologic changes seen in the breast? (Robbins p. 1042)
Cystic change, often with apocrine metaplasia
Fibrosis
Adenosis
List 5 benign causes of calcifications in the breast
Sclerosing Adenosis Apocrine metaplasia Cysts (ruptured) Hyalinized fibroadenoma Fat necrosis
List 3 proliferative breast diseases without atypia with a 1.5 - 2x increased relative risk of cancer.
Sclerosing adenosis
UDH
Complex fibroadenoma (>3mm, sclerosing, calcs, papillary apocrine change)
Name 7 germline mutations of high penetrance are associated with breast cancer?
BRCA1 BRCA2 TP53 Li Fraumeni PTEN Cowden STK11 Peutz-Jeghers CDH1 Hereditary diffuse gastric PALB2 Hereditary breast cancer
Robbins p. 1049
Name two germline predispositions to breast cancer that are of only moderate penetrance.
ATM (Ataxia-Telangiectasia)
CHEK2 (hereditary breast cancer)
Robbins p. 1049
Name two other cancers that are seen due to BRCA1 & BRCA 2 germline mutations:
pancreas
prostate
Which hereditary germline mutation is most frequently associated with male breast cancer?
BRCA2
What is the most common molecular subtype of breast carcinoma seen in Li Fraumeni patients? (i.e. Luminal, Her2 enriched, or triple negative).
Her2 enriched
Robbins p. 1051
Name some pre-analytic and analytic variables that affect breast biomarker reporting (7 listed in CAP).
Cold ischemia (1hr) and formalin fixation times (6-72hrs)
Type of fixative (if other than buffered formalin)
Treatments that could alter immunoreactivity (e.g. decal).
Status of internal (normal epithelial cells) and external controls.
Adequacy of sample
Primary antibody clone
Regulatory status (FDA-cleared vs laboratory-developed test).
List reasons for false-negative hormone receptor results in breast carcinoma
(CAP breast biomarker reporting protocol p. 9)
Artifacts make interpretation difficult
“Inadequate specimen handling”
Failure of internal and/or external positive controls
Exposure to heat; cautery during surgery Prolonged cold ischemia time (>1hr) Under/over fixation (<6, >72hrs) Type of fixative: ER degraded in acidic fixatives like B5, Bouin; formalin pH should be between 7.0 and 7.4 Decalcification Nonoptimized antigen retrieval Type of antibody Dark hematoxylin counterstain obscuring faint positive DAB staining
List reasons for false-positive hormone receptor results in breast carcinoma
(CAP protocol breast Biomarker reporting)
impure antibody cross-reacts with another antigen
misinterpretation of entrapped normal cells or an in-situ component as invasive carcinoma
use of image analysis devices that count overstained nuclei
List 3 things to pay careful attention to in order to avoid false positive and false negative results in breast biomarker reporting.
Staining of normal breast epithelial cells
External controls
Correlation with histologic type and grade of the cancer
What is the threshold to call ER or PR positive?
1%
What proportion of breast carcinomas overexpress HER2?
15-20%
List 2 ways that HER2 is assessed
Immunohistochemistry: protein expression on membrane.
In-situ hybridization: gene copy number.
List 4 causes of false-POSITIVE IHC results for HER2.
Edge artifact: antibody pools at sides (esp. in core biopsies); stronger staining at the edge of tissue should be interpreted with caution.
Cytoplasmic positivity: can obscure membrane staining
Overstaining: strong membrane staining of normal cells (may be due to improper antibody titration/concentration too high).
Misinterpretation of DCIS: high grade DCIS is often HER2+. With extensive DCIS, this may be misinterpreted as invasive carcinoma.
List 3 causes of false-NEGATIVE IHC results for HER2.
Prolonged cold ischemia time.
Tumor heterogeneity. Suspect this especially if the tumor has characteristics of HER2+ tumors, such as high grade, weak/negative ER/PR, high ki67)
Improper antibody titration (concentration too low)
Define Scores of 0, 1, 2, and 3+ for HER2 by IHC.
0: no staining; OR membrane staining that is incomplete and faint/barely perceptible and <10% of tumor cells.
1: Incomplete; faint/barely perceptible in >10% of cells
2: Complete but weak/moderate in >10% of tumor cells,
OR complete but <10%
3: Complete membrane staining that is intense and >10% of cells.
What are the parameters using to test HER2 by ISH?
HER2/CEP17 ratio
HER2 signals/cell
List 4 causes of false negative results for HER2 testing by ISH?
Prolonged fixation (>1week)
Fixation in non-formalin fixatives
Procedures or fixation involving acid (e.g. decal) that may degrade DNA
Insufficient protease treatment of tissue.
What is the definition of microinvasion in the breast?
Invasion less than or equal to 1mm
What is the tumor stage of Paget disease of the nipple with skin involvement only (no underlying invasive or DCIS)?
pTis
List the 6 nuclear morphologic features used to grade DCIS:
- Pleormorphism
- Size
- Chromatin
- Nucleoli
- Mitoses
- Orientation
“Parents Say Carrots Not Marshmallows & Oreos”
“Please Send Cash Now Mommy Overseas”
List two ways that necrosis is classified (two possible architectures) in DCIS.
Central / “comedo” : central necrosis with ghost cells and karyorrhectic debris, obvious at low power
Focal / punctate : small, indistinct; single cell necrosis.
Necrosis is important in DCIS because it correlates with mammography; also DCIS that presents as mammographic calcs often recurs the same way.
What are the 2 ways that Extensive Intraductal Carcinoma is defined?
What is the significance of EIC?
- DCIS is a major component within the area of invasive carcinoma (approx. 25%) and DCIS is ALSO present in the surrounding breast parenchyma.
- DCIS associated with a small (~10mm or less) invasive carcinoma (i.e. the invasive carcinoma is too small for the DCIS to involve 25%).
Significance: greater risk of recurrence if close margins (or no margin assessment).
List 5 ways that involvement of the skin by carcinoma is classified, and their effect on T-stage.
Paget disease (DCIS involving nipple epidermis); pTis if NOT associated with underlying DCIS or invasive carcinoma. NB when there is an underlying DCIS or invasive then it is reported but does not change the T-stage of the parenchymal disease.
Invasion into dermis or epidermis, without ulceration; does not change pT.
Invasion into dermis or epidermis, with ulceration; pT4b.
Ipsilateral satellite skin nodules; pT4d
Dermal lymphovascular invasion; pT4d.
(Clinically, inflammatory carcinoma.)
What the chest wall structures that must be invaded for a designation of pT4a?
Intercostal muscles
What are the 4 criteria for LVI in the breast, according to the CAP? (more like suggestions to recognize LVI)
- LVI must be outside the border of the invasive carcinoma
- tumor emboli do not conform exactly to the shape of the space in which they are found (unlike tumor retraction)
- Endothelial cell nuclei should be seen lining the space.
- Lymphatics are often found adjacent to blood vessels and often partially encircle a blood vessel.
What are the two defining features of Comedo DCIS?
Robbins p. 1053
Tumor cells with pleomorphic, high-grade nuclei
Central necrosis
CAP: central duct space expanded by necrosis at low power; contains GHOST cells and KARYORRHECTIC debris.
List 5 papillary lesions of the breast.
Benign intraductal papilloma
Intraductal papilloma with ADH or DCIS
Papillary DCIS
Encapsulated papillary carcinoma
Solid papillary carcinoma
Define FOCAL and EXTENSIVE involvement of margins with DCIS.
FOCAL: <1mm in 1 block at margin
EXTENSIVE:
> /= 15mm
more than 5 low power fields
8 blocks with DCIS at the margin.
