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