GCDFP15 reactivity is generally considered to be strong and universal in apocrine lesions
Such reactivitiy is taken by some to define apocrine differentiation
Note that the criteria employed by Japaze et al. are not based on immunologic reactivity
PASd may show granular cytoplasmic positivity
Demonstration of myoepithelial cells can confirm the in situ nature of a process while their absence supports invasion
We prefer to use both p63 and calponin on problematic cases
A variety of markers have been used for myoepithelial cells:
Marker
Sensitivity
Specificity
Calponin
Excellent
Very good
p63
Excellent
Excellent
Smooth muscle myosin heavy chain
Good
Excellent
CD10 (CALLA)
Good
Good
High molecular weight cytokeratin
Very good
Poor
Maspin
Good
Poor
S100
Good
Very poor
Actin
Good
Very poor
E-cadherin appears to be a sensitive marker of ductal differentiation vs lobular differentiation; its utility in borderline lesions is currently uncertain
Immunologic markers useful for identification of breast carcinoma
GCDFP15 (BRST2)
Estrogen Receptor
Progesterone Receptor
PAX8
Infiltrating ductal carcinoma
60-70%
75%
50-60%
0%
Infiltrating lobular carcinoma
60-70%
>95%
80%
0%
Lung adenocarcinoma
0-1%
<5%
<5%
0%
Ovarian adenocarcinoma
1-5%
50-100%
40-90%
90-100%
Endometrioid adenocarcinoma
negative
70%
70%
GI adenocarcinoma
negative
<5%
1-10%
0%
Pancreatic adenocarcinoma
negative
negative
0-5%
0%
Cholangiocarcinoma
negative
negative
30%
Thyroid carcinoma
negative
20%
30%
100%
Sweat gland and salivary gland neoplasms may also be positive for GCDFP15, ER and PR
Prostatic adenocarcinoma may be positive for GCDFP15
CK7 and CK20 have not been tested on a series of apocrine carcinomas, thus their utility is unknown
Prognostic/Therapeutic Markers
Estrogen receptor (ER) and progesterone receptor (PR) are important markers for directing therapy and determining prognosis
Current consensus is that any level of positivity should be reported as positive
Her2neu status can be determined by either immunohistology or by FISH
The other technique can be used for borderline case
Genetic analysis
Her2neu status can be determined by either immunohistology or by FISH
The other technique can be used for borderline cases
