Chapter 29 - A Primer on Immunostains Flashcards
CD31
Endothelial cells and megakaryocytes (cytoplasmic and membranous), also macrophages
To identify endothelial differentiation or angiosarcoma (most specific endothelial marker)
CD34
soft tissue
Endothelial cells, fibroblasts, and hematopoietic blasts (cytoplasmic and membranous)
To identify vascular sarcomas, Kaposi’s sarcoma, GIST, SFT, DFSP, epithelioid sarcoma, and some other soft tissue tumors. Synovial sarcoma is negative.
FVIII
blood vessels
Endothelial cells, megakaryocytes, platelets (cytoplasmic)
To identify endothelial differentiation
EMA
Epithelial, perineural, meningothelial cells (cytoplasmic or membranous)
To identify meningioma, perineuroma, chordoma, mesothelioma, sebaceous carcinoma and some sarcomas (synovial, epithelioid) and plasma cell neoplasms.
Name some entities that are EMA positive, keratin negative.
Meningioma, perineuroma, plasma cell myelomas.
GFAP
Glial cells (cytoplasmic)
To identify astrocytoma, GBM, ependymoma, and myoepithelial tumros of salivary gland. OGD and neuroblastoma are negative.
NSE (Neuron-specific enolase)
Neuroectodermal and neuroendocrine cells (cytoplasmic)
To identify neural differentiation but not very specific. Sensitive for neuroblastoma.
S-100
Glial cells, shwann cells, dendritic and langerhans cells, melanocytes, other mesenchymal cells (cytoplasmic and nuclear)
To identify schwannoma, gliomas, granular cell tumor, chordoma, ependymoma, MPNST, and melanocytic lesions. Breast can be positive.
Synaptophysin
Neuroendocrine cells (cytoplasmic)
To identify carcinoid, paraganglioma, pheochromocytoma, small cell, medullary carcinomas, neuroblastoma, islet cell tumors…
E-cadherin
Normal ductal and lobular cells (membranous)
Loss of staining identifies lobular carcinoma.
ER/PR
Estrogen receptor (nuclear) and progesterone receptor (nuclear)
For breast cancer prognosis (response to tamoxifen) and to identify metastatic breast cancer and some gynecologic tumors.
GCDFP
Apocrine metaplasia of breast and apocrine sweat glands (cytoplasmic)
To identify breast carcinoma and sweat/salivary gland carcinoma.
Her2Neu
Growth factor receptor, weakly expressed on normal epithelium (membranous and cytoplasmic)
To evaluate breast carcinomas (poor prognosis, response to trastuzumab)
Ki67
breast
Any proliferating cell (nuclear)
To gauge mitotic activity for prognosis
Alpha-actin
breast
Smooth muscle: myoepithelial cells, blood vessels, myofibroblasts (cytoplasmic)
To delineate myoepithelial layer and rule out invasive cancer
p63
breast
Tumor suppressor gene (nuclear)
Stains myoepithelial cells but not endothelial and fibroblasts (cleaner than actin/SMMHC). Also stains metaplastic carcinoma.
CK903
breast
Myoepithelial cells (cytoplasmic and membranous) and usual ductal hyperplasia
To differentiate usual ductal hyperplasia from DCIS. Also stains metaplastic carcinoma.
AE1/AE3
Wide panel of keratins, except 8+18 (cytoplasmic).
To identify carcinomas in general in conjunction with Cam5.2
Cam5.2
Low and intermediate-weight keratins 8, 18, and 19 (cytoplasmic)
To identify carcinomas in general in conjunction with AE1/AE3. Also identifies hepatocellular carcinoma, some adrenal cortical tumors, and some other carcinomas.
CK5/6
Two specific high-molecular-weight keratins (cytoplasmic)
To differentiate squamous cell carcinoma or mesothelioma from adenocarcinoma (negative).
CK7
A specific low-molecular-weight cytokeratin (cytoplasmic)
Positive in above-the-diaphragm carcinomas. Used in conjunction with CK20.
CK20
A specific low-molecular-weight cytokeratin (cytoplasmic)
Positive in below-the-diaphragm carcinomas and Merkel cell carcinoma. Used in conjunction with CK7.
What carcinomas are CK7+/CK20+?
Urothelial carcinoma
Pancreatic carcinoma
Ovarian mucinous carcinoma
What carcinomas are CK7+/CK20-?
Breast carcinoma NSCLC Ovarian serous carcinoma Endometrial carcinoma Epithelial mesothelioma Thymoma
What carcinomas are CK7-/CK20+?
Colorectal carcinoma
Merkel cell carcinoma
What carcinomas are CK7-/CK20-?
Hepatocellular carcinoma CCRCC Prostate carcinoma Neuroendocrine small cell carcinoma Squamou cell carcinoma
AFP
germ cell and testis
Fetal tissues (cytoplasmic)
To identify yolk sac tumor and HCC
c-KIT
Germ cells, mast cells, interstitial cells of Cajal (cytoplasmic or membranous)
To identify seminoma, mature teratoma, and GIST
b-hCG
Syncytiotrophoblasts (cytoplasmic)
To identify choriocarcinoma and germ cell tumors, some adenocarcinomas
HPL
Trophoblasts (cytoplasmic)
To identify germ cell tumors, moles, and choriocarcinoma.
Ki-1 (CD30)
Activate lymphocytes
To identify embryonal carcinoma, Hodgkin’s lymphoma, and ALCL
PLAP
Placenta (cytoplasmic)
To identify germ cell tumors, ITGCN. Does not stain spermatocytic seminoma.
CA-125
(no normal tissue stains)
To identify nonmucinous ovarian carcinomas
Inhibin
Granulosa cells, Sertoli cells, others (cytoplasmic)
To identify sex cord stromal tumors (Granulosa, Sertoli, Leydig) and moles, choriocarcinomas, fibrothecomas, and adrenal cortical tumors
Melcam (CD146)
Intermediate trophoblasts
To identify PSTT, choriocarcinoma
Mesothelin
Mesothelial cells (membranous)
To identify serous ovarian carcinoma, mesothelioma, and pancreatic carcinoma (targetable for immunotherapy?)
p16
Cells infected by HPV (nuclear)
To identify HSIL & HPV lesions of cervix and to differentiate endocervical (positive) and endometrial (negative) adenocarcinoma
p53
Tumor suppressor gene variant that should be absent in normal cells (nuclear)
To identify EIC and serous carcinoma of endometrium
ALK
Fusion protein only expressed by lymphomatous cells
Stains a subset of ALCL and DLBCL. HL is negative.
BCL-2
Inhibits apoptosis, normally turns off in germinal center (cytoplasmic & membranous)
To differentiate follicular lymphoma from reactive follicles. Also stains mantle cell lymphoma. Burkitt’s is negative.
BCL-6
Germinal center cells (cytoplasmic)
To identify lymphomas of follicular origin (FCC, Burkitt’s lymphoma)