IHC Flashcards
GFAP
Cytoplasmic and cell processes of astrocytes
Nestin
intermediate filament in embryonic nerve cells and hair follicle stem cells (can differentiate into multiple types of cells), proliferating new endothelial cells. Cytoplasm.
Synaptophysin
Neuroendocrine: Adrenal medulla, neuronal cells, neuroendocrine cells, pineal gland. Membrane and cytoplasm (integral membrane protein and pre-synaptic vesicles)
Vimentin
intermediate filament of mesenchymal cells; cytoplasm
Neurofilament
Neurons; cytoskeletal component of axons and dendrites
SOX-10
Transcription factor; neural crest derived tissues; expressed by melanocytes, mammary myoepithelial cells and Schwann cells. Melanoma & neural crest marker!
TTF-1
Thyroid Transcription Factor 1; found in the nucleus only! Thyroid, lung and diencephalic brain (thalamus/hypothalamus/pineal/pituitary) structures.
Chromogranin
secretory vesicles of neuroendocrine cells; Adrenal medulla (chromaffin cells), heart AV node, pancreas (islets), parathyroid (chief cells), thyroid (C cells)
Desmin
Intermediate filament in cardiac, smooth and skeletal muscle (GISTs are negative)
CD31/PECAM
PECAM; Membranous expression! Endothelial cells at cell junctions, megakaryocytes, pericytes, platelets, brown fat, trophoblasts, fibroblasts, spermatozoa, surface of platelets, monocytes, neutrophils and some types of T cells. key role in leukocyte trafficking across endothelium
Calponin
Actin-filament associated protein; Smooth muscle, myoepithelial cells, myofibroblasts, keratinocytes and nerve fibers
Alkaline Phosphatase
sarcoplasm of regenerating myofibers and cytoplasm of arteriole endothelial cells (not capillaries)
CD79a
B cells / B cell origin (with CD20) including plasma cells. May be positive when CD20 is negative.
CD20
B cells (not plasma cells)
CD45
also called leukocyte common antigen; NUCLEATED HEMATOPOIETIC CELLS (so not RBC’s, megakaryocytes or PLT’s).
CD18
leukocyte adhesion protein (deficiency leads to LAD); Neutrophils, macrophages, monocytes, NK cells and basophils
CD3
Thymocytes, peripheral T cells, NK cells (early cytoplasmic staining, then membranous)
c-KIT
AKA CD 117; proto-oncogene activated in GISTs and Mast Cell Tumors; cytoplasmic expression. Also found in interstitial cells of Cajal, hematopoietic progenitor cells, melanocytes, embryonic/fetal brain, endothelium, gonads, breast epithelium, germ cells.
S-100
show nerve sheath involvement (i.e Schwann cell) or melanocytic origin; neurons, myoepithelial cells, adipocytes, langerhans/ tissue and interdigitating dendritic cells, chondrocytes and notochord
PNL-2
melanocytes; cytoplasm
Melan-A
AKA MART1; cytoplasm. Anything that forms melanosomes.
DOG-1
GISTs only. Discovered On Gists 1. Membrane & cytoplasm.
Ki67
proliferation index during G1, S, G2 and M phases of cell cycle. Not found in G0 and early G1. Nuclear stain is the only one that “counts”.
CK AE1/AE3
Epithelial cells and trophoblasts; Detects CK1-8, 10, 14-16 and 19
CK 34BE12
Squamous, transitional and some ductal epithelium
CK5/6
Mammary myoepithelial cells, cornea, mesothelium, basal epithelium
CK 7
Glandular and transitional epithelium
CK 8/18
Carcinomas of epithelial origin and mesotheliomas
CK 20
Gastric, intestinal, urothelial epithelium and Merkel cells
Doublecortin
neurons
E-cadherin
decreased in carcinoma
Argyrophilic Nucleolar Organizer Region (AgNOR)
Proliferation marker; increased nucleolar silver stained dots increases the potential for malignancy
Calretinin
Adipocytes, mesothelial cells, endometrial stroma, Leydig cells, mast cells, nerves, ovarian theca cells, Sertoli cells
HMB-45
Melanocytes
Iba-1
Macrophages/histiocytes/microglia
Inhibin
Sertoli cells, granulosa cells, prostate, brain, adrenal gland
Laminin
Basement membrane
Tyrosinase-related protein-1 (TRP1) and 2 (TRP2)
melanocytes
Uroplakin I, II, III
urothelium
WT-1 (Wilms tumor)
Nephroblastoma
Luminal A
ER (+)
PR (+)
HER2 (-)
Luminal B
ER (+)
PR (+)
HER2 (+)
HER2
ER (-)
PR (-)
HER2 (+)
Basal-like
ER (-)
PR (-)
HER2 (-)
Perform CK5/6 and EGFR to define more precisely tumors in basal-like group
Luminal
Molecular category of Breast cancer with high expression of hormone receptors and associated genes (luminal A > luminal B)
HER2
Molecular category of breast cancer with high expression of HER2 and other genes in amplicon. Low expression of ER and associated genes.
Basal-like
Molecular category of breast cancer with high expression of basal epithelial genes, basal cytokeratins; low expression of ER and associated genes; low expression of HER2.
BRCA1-associated cancers
Carcinoma
PanCK (+)
LCA (-)
S100/HMB45/MART-1 tyrosinase (-)
Desmin (-)
Vimentin (-)
Lymphoma
PanCK (-)
LCA (+)
S100/HMB45/MART-1 tyrosinase (-)
Desmin (-)
Vimentin (-)
Melanoma
PanCK (-)
LCA (-)
S100/HMB45/MART-1 tyrosinase (+)
Desmin (-)
Vimentin (+)
Sarcoma
PanCK (-)
LCA (-)
S100/HMB45/MART-1 tyrosinase (-)
Desmin (+)
Vimentin (+)
Desmin, HHF35, SmActin
Smooth muscle
Myoglobin
Skeletal muscle
CD68, Factor XIIIa
Fibrohistiocyte
Leu7, GFAP
Nerve sheath
Factor VIII, CD34, CD31
Endothelial, perivascular
LCA, CD3, CD20
Hematopoietic
NSE, Chromogranin
Neuroendocrine
MIC-2(O-13), CD99
Ewing’s sarcoma/PNET
Lung lesion showing mostly isolated small cells with pyknotic nuclei. What is the diagnosis?
Lymphoma: CK(-) LCA (+)
Small cell cancer: CK(+) LCA(-)
What is the diagnostic approach to Metastatic Carcinoma of Unknown Primary?
- Find the cell line of differentiation using major lineage markers
- Find the CK type distribution in tumor cells
- Find if there is co-expression of vimentin
- Find if there is expression of supplemental antigen of epithelial or germ cell derivation (CEA, EMA, PLAP)
- Find if there is expression of cell-specific products, cell-specific structures or receptors that are unique identifiers of cell types (GCDFP, PSA, TTF-1)
CK7+/CK20+
Transitional cell carcinoma
Pancreatic carcinoma
Ovarian mucinous carcinoma
50% of gastric CA
CL7-/CK20+
Colorectal adenocarcinoma
Merkel cell carcinoma
CK7+/CK20-
Non-small cell cancer of the lung
Small cell cancer of the lung
Breast cancer, ductal and lobular
Nonmucinous ovarian cancer
Endometrial adenocancer
Mesothelioma
Squamous cell cancer of the cervix
CK7-/CK20-
Squamous cell cancer of the lung
Prostate adenocancer
Renal cell cancer
Hepatoma
Thymus
Prostate (MCUP)
PSA
Se 100
Sp 99
Lung (MCUP)
TTF-1
Se 91
Sp 98
Colon
CDX-2
Se 83
Sp 96
CK20
Se 68
Sp 91
Colon and stomach
CDX-2
Se 56
Sp 98
Colon, stomach, pancreas
CK20
Se 36
Sp 97
Breast
GCDFP-15
Se 54
Sp 96
Breast and ovary
ER
Se 74
Sp 95
Ovary and pancreas
CA 125
Se 88
Sp 88
Mesothelin
Se 85
Sp 85
Stomach and pancreas
Lysozyme
Se 65
Sp 69
CK 7
Se 72
Sp 96
Work-up lineage for lymphoma
CD20+: B cell lymphoma
CD3+: T cell or NK cell lymphoma
CD20-/CD3-: nonhematolymphoid, plasmacytoma, anaplastic lymphoma, t cell lymphoma, lymphoblastic lymphoma
TdT
Important markers for classifying lymphomas:
Precursor lymphoblastic lymphoma
CD5, CD23
Important markers for classifying lymphomas:
Chronic lymphocytic lymphoma
Cyclin D1 (aka BCL-1 and PRAD): nuclear positivity
Important markers for classifying lymphomas:
Mantle cell lymphoma
CD10 (or BCL-6)
Important markers for classifying lymphomas:
Follicular lymphoma
Ki67 (~100% proliferation index)
Important markers for classifying lymphomas:
Burkitt lymphoma
CD10, follicular dendritic cell markers (extrafollicular meshworks)
Important markers for classifying lymphomas:
Angioimmunoblastic T cell lymphoma
CD30, ALK
Important markers for classifying lymphomas:
Anaplastic large cell lymphoma
Biomarkers in prostate CA
PSA - cytoplasmic expression in glandular epithelium
Basal cell markers - p63, HMW-CK
Alpha-methyl-CoA racemase (AMACR) - recently identified as being overexpressed in prostatic adenocarcinoma (80%)
GCDFP-15
Gross cystic disease fluid protein - 15
IHC panel of small round cell tumors in children
CK - carcinoma
LCA - lymphoma
Desmin - rhabdomyosarcoma
CD99 - Ewings sarcoma/PNET
IHC panel of small round cell tumors in adults
CK - carcinoma
LCA - lymphoma
Vimentin, S100 - sarcoma
Chromogranin/Synaptophysin - PNET
IHC panel of endometrial and endocervical, primary
Both: CK7(-)/CK20(+)
Endocervical: p16, CEA
Endometrial: vimentin, ER
IHC panel in subclassification of the most common lung cancers
SCCA: p63, CK5/6, CK7(-)
AdenoCA: TTF-1, CK7(+)
Small cell: chromogranin/synaptophysin, variable CK positivity
IHC panel of atypical small acinar proliferation in prostate biopsy cases.
AMACR
Myoepithelial markers: p63, 34BA12 or HMWCK, SMA
IHC panel of DCIS vs Invasive Ductal Carcinoma breast biopsy cases
Myoepithelial markers: p63, actin, SMA
CK5/6: (+)ADH with low grade DCIS
IHC panel of mature B cell neoplasm
Follicular lymphoma: Bcl-2
MALT: cytokeratin
3
4
5
IHC panel in differentiating HL from NHL
LCA
CD30: golgi and cytoplastmic membrane
CD15: golgi and cytoplasmic membrane
CD20
CD3
Fascin (cytoplasmic expression in HL)
IHC panel in differentiating lung, thyroid, hepatocellular, primary.
Thyroid:
CK7+/CK20-
TTF-1(+): nuclear
TGB(+): cytoplasmic
Lung:
CK7+/CK20-
TTF-1(+): nuclear
TGB(-): cytoplasmic
Liver:
CK7-/CK20-
AFP: poorly diff hepatocellular CA
Hepar-1: well to mod diff hepatocellular CA
Pattern of bcl-2 expression in reactive lymphadenopath
Interfollicular and paracortical
Pattern of bcl-2 expression in follicular lymphoma
Within the follicles
CD56 (NCAM)
NSE
Olfactory neuroblastoma
Medium-sized lymphoma
Lymphoblastic lymphoma: TdT
Follicular lymphoma
Positive for HMB-45
Epitheloid angiomyolipoma
Melanoma
RCC, CD10
Renal cell CA
CD19
The earliest IHC marker for B-lineage differentiation.
CD20
Acquired late in pre-B-cell stage of maturation; lost at the plasma cell stage.
CD20: cytoplasmic staining
Strongly positive: half of lymphoblastic lymphoma/leukemia; all mature B-cell lymphomas; Reedsternberg cells in 1/4 cases of HL
CD21
IHC marker found in follicular dendritic cells and some B lymphocytes; helps identify the hyperplastic islands of dendritic cells in angioimmunoblastic T-cell lymphoma.
CD22
IHC marker strongly expressed in hairy cell leukemia.
CD23
IHC marker that is most useful in distinguishing B-cell CLL/SLL from other entities and remains present in CLL/SLL that has undergone large cell transformation.
CD79a
Expressed in nearly all of the assayed precursor B-cell lymphoblastic lymphoma/leukemias, with no T-cell staining. Also positive in mature B-cell lymphomas.
DBA.44
Strongly stains the cytoplasm of most hairy cell leukemias, marginal zone lymphomas, and large cell lymphomas
CD2
IHC marker for early T-cell antigen in a normal lymph node.
CD3 (cell membrane
Positive with most T-cell lymphomas except anaplastic large cell lymphomas and NK leukemias/lymphomas. Very specific for T-cell derivation.
CD4
It interacts with HLA class II during antigen recognition, and defines a helper-inducer subset of T cells. Expressed in most mature T-cell lymphomas.
CD5
Detectable on the surface of most thymocytes and immature peripheral T cells and in a small subset of circulating B cells. Primarily used in the detection of B cell CLL/SLL and mantle cell lymphoma.
CD7
It has the distinction of being the most frequently lost T-subset marker in malignancies, particularly on mycosis fungiodes.
Also present on non-T-cell malignancies, including NK tumors and AML
CD8
This antigen defines the suppressor/cytotoxic T-cell subset
t(2;5)
Anaplastic large cell lymphoma
t(11;14)
Mantle cell lymphoma
Cyclin D1 (aka BCL-1 and PRAD 1): nuclea
Hallmark of mantle cell lymphomas. Weaker signal in hairy cell leukemia and plasmacytoma.
t(14;18)
Follicular lymphoma
Found in app 3/4 of cases of follicular lymphoma.
BCL-2: stains malignant follicles
Reversed pattern in lymph nodes exhibiting follicular hyperplasia
BCL-2
Normally present in the cytoplasm of follicular mantle B lymphocytes, occasional germinal center cells, and many T lymphocytes
BCL-6
Expressed normally in germinal center lymphocytes.
Expressed in a variety of B-cell neoplasms. Also detected in L&H variants of nodular lymphocyte predominant Hodgkin disease.
CD1a
Ag associated with beta 2 macroglobulin. Found in a subset of precursor T-lymphoblastic lymphoma/leukemia.
CD10 (CALLA)
Almost always present on the surface of precursor B lymphoblastic and Burkitt’s lymphomas, many FL and some DLBCL along with MM
CD15
X hapten or Lewis X antigen
CD15: membranous with a paranuclear dot-like Golgi localization
Marker for RS cells of classical HL. Also used to stain adenocarcinomas.
CD25
IL-2 receptor. Expressed on hairy cell leukemia and adult T-cell leukemia/lymphoma.
Burkitt’s lymphoma
Ki-67 index (nuclear staining)
Follicular lymphoma
BCL-2 positivity in enlarged follicles
Reactive hyperplasia
BCL-2 positivity around follicles
TdT
Almost always present in the nucleus of lymphoblastic lymphoma cells
CD20+
BCL-2+
Mantle cell lymphoma
Follicular lymphoma
Some marginal zone lymphoma
B-CLL/SLL vs Mantle cell lymphoma
B-CLL/SLL:
CD23 (+)
Cyclin D1 (-)
Mantle cell lymphoma:
CD23 (-)
Cyclin D1 (+)
B-CLL/SLL vs Follicular lymphoma
B-CLL/SLL:
CD10 (-)
CD5/CD43 (+)
ZAP-70
Predicts poor outcome in B-CLL
Mature B lymphocytes vs plasma cells
Mature B lymphocytes:
CD45RB (+)
CD20 (+)
BCL-2
Sensitive for follicular lymphoma but not specific