Immunostains Flashcards
CD31
Stains:
Endothelial cells and megakaryocytes
(cytoplasmic and membranous), also
macrophages.
Used:
To identify endothelial differentiation or angiosarcoma;
most specific endothelial marker.
CD34
Stains:
Endothelial cells, fibroblasts, and
hematopoietic blasts (cytoplasmic
and membranous).
Used:
To identify vascular sarcomas, Kaposi sarcoma, solitary
fibrous tumor, DFSP (dermatofibrosarcoma protuberans), epithelioid sarcoma, plus some other soft tissue tumors. Synovial sarcoma is negative
D240
**Stains:** Lymphatic endothelium (cytoplasmic).
Used:
To identify vascular differentiation or lymphatics; also
marks mesothelium
FVIII
Stains:
Endothelial cells, megakaryocytes,
platelets (cytoplasmic).
Used:
To identify endothelial differentiation, specific but not
very sensitive
CK903 (CK5/6 is similar)
Stains:
Myoepithelial cells (cytoplasmic and membranous) and usual duct hyperplasia; High-molecular-weight keratins, mainly
in squamous and urothelial epithelia (cytoplasmic and membranous)
Used:
To differentiate usual ductal hyperplasia (positive) from ductal carcinoma in situ (negative). Also stains metaplastic carcinoma. To identify prostatic basal cells (loss of staining
indicates carcinoma) and urothelial carcinoma (positive); also metaplastic breast carcinoma
E-cadherin
Stains:
Normal ductal and lobular cells (membranous)
Used:
Loss of staining identifies lobular carcinoma (in situ and invasive); ductal lesions are positive
ER and PR
**Stains:** Estrogen receptor (nuclear) and progesterone receptor (nuclear)
Used:
For breast cancer prognosis (predicts response to tamoxifen) and to identify metastatic breast cancer, some gynecologic tumors, and others
GATA3
**Stains:** Breast epithelium (nuclear
Used:
To identify breast differentiation in carcinoma; sensitive but not specific
GCDFP
Stains:
Apocrine metaplasia of the breast and apocrine sweat glands (cytoplasmic)
Used:
To identify breast differentiation in carcinoma, also sweat and salivary gland carcinoma
Her2
Stains:
Growth factor receptor that is only weakly expressed in normal epithelial cells (membranous)
Used:
To evaluate breast carcinomas (overexpression is a poor prognostic sign but can be treated with Herceptin)
Mammoglobin
Stains:
Normal breast tissue (cytoplasmic)
Used:
To identify breast differentiation in carcinoma, also sweat and salivary gland carcinoma
Calponin
**Stains:** Myoepithelial cells (cytoplasmic)
Used:
To delineate myoepithelial layer to identify myoepithelial cells to rule out invasive carcinoma
p63
Stains:
Tumor suppressor gene (nuclear)
Used:
To identify myoepithelial cells to rule out invasive carcinoma.Stains myoepithelial cells but not endothelium and fibroblasts. Also stains metaplastic carcinoma.
Smooth muscle myosin heavy chain (SMMHC)
Stains:
Myoepithelial cells, blood vessels, myofibroblasts (cytoplasmic)
Used:
To identify myoepithelial cells to rule out invasive carcinoma. To delineate myoepithelial layer
Smooth muscle actin (SMA)
Stains:
Smooth muscle: myoepithelial cells, blood vessels, myofibroblasts (cytoplasmic)
Used:
To identify myoepithelial cells to rule out invasive carcinoma. To delineate myoepithelial layer; also stains myofibroblasts
Calcitonin
Stains:
C cells of the thyroid (cytoplasm and extracellular material)
Used:
To identify medullary carcinoma of the thyroid
PAX8
Stains:
Renal and Mullerian tissues (nuclear)
Used:
To identify anaplastic carcinoma of thyroid and other
thyroid carcinomas
Thyroglobulin
**Stains:** Thyroid follicles (cytoplasmic)
Used:
To identify metastatic thyroid carcinoma
TTF-1 (thyroid transcription factor)
Stains:
Transcription factor in the lung and thyroid (nuclear)
Used:
To identify thyroid carcinoma, including follicular,
papillary, and medullary; also nonsquamous carcinoma
of the lung (adenocarcinoma and small cell)
AE1-AE3 (pankeratin)
Stains:
Wide panel of keratins stains most epithelial cells (cytoplasmic), except cytokeratins 8 and 18
Used:
To identify carcinomas in general; used in conjunction with cam 5.2 to screen for carcinoma
EMA
Stains:
Epithelial, perineural, meningothelial cells (cytoplasmic or membranous)
Used:
To identify meningioma, many carcinomas, plus some sarcomas (synovial sarcoma, epithelioid sarcoma), and plasma cell neoplasms. Germ cell tumors (excluding some teratomas) are negative
Entities that are EMA-positive, keratin-negative: meningioma, perineuroma, plasma cell myeloma
CK5/6
Stains:
High-molecular-weight keratins, mainly in squamous and urothelial epithelia (cytoplasmic)
Used:
To differentiate squamous cell carcinoma (positive) or mesothelioma (positive) from adenocarcinoma
(negative)
CK7
Stains:
A specific low-molecular-weight cytokeratin (cytoplasmic, membranous)
Used:
CK7 and CK20 are used in combination to narrow the differential of carcinoma of unknown origin. CK7 is generally positive in above-the-diaphragm carcinomas (see below on CK7 and CK20)
CK20
Stains:
A specific low-molecular-weight cytokeratin (cytoplasmic, membranous)
Used:
Generally positive in below-the-diaphragm carcinomas and in Merkel cell carcinoma (see below on CK7 and CK20)
Cam 5.2
Stains:
Low- and intermediate-molecular-weight keratins 8, 18, and 19, in nonsquamous epithelia (cytoplasmic)
Used:
Used in conjunction with AE1/AE3 to screen for carcinoma. Also to identify hepatocellular carcinoma, some adrenal cortical tumors, and some carcinomas that are negative for other keratins (undifferentiated carcinoma)
CK 7/20 Matrix
7+20+; 7+20-
7-20+; 7-20-
7+20+: urothelial carcinoma, pancreatic carcinoma, ovarian mucinous carcinoma
7+20-: breast carcinoma, lung carcinoma (non-small cell), ovarious serious carcinoma, endometrial carcionma, epithelial mesothelioma, thymoma
7-20+: Colorectal carcinoma, merkel cell carcinoma
7-20-: Hepatocellular carcinoma, renal cell carcinoma (clear cell type), prostate carcinoma, neuroendocrine small cell carcinoma, squamous cell carcinoma
