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Stains A-E
Routine stains, immunostains and molecular markers
Revised: 2 July 2009
Authors: Kara Hamilton,.Nat Pernick, M.D., PathologyOutlines.com, Inc.
Copyright: (c) 2002-2009, PathologyOutlines.com, Inc.
See also CD Marker chapters
Note: stains/proteins are in alphabetical order, with numbers before letters, and ignoring dashes and spaces
Primary references, immunohistochemistry basics, common panels, biopsy interpretation, enzyme cytochemistry
Note: the chapter has many more topics than are included in the table of contents, which is being updated
A: acid fast bacilli; actins: general, muscle specific; alpha-1-antitrypsin, alpha-fetoprotein
B: B72.3, beta-catenin, BG8
C: caldesmon, calponin, calretinin
Cytokeratins: general, CK1, CK2, CK3, CK4, CK5, CK6, CK7, CK8, CK9, CK10, CK11, CK12, CK13, CK14, CK15, CK16, CK17, CK18, CK19, CK20, CK21, CK22, CK23, CK24, 34betaE12, 35betaH11, AE1, AE3, AE1-AE3, CAM5.2, KL-1, MNF116, OSCAR
E:
Go to Stains F-Z and cell cycle
American Journal of Surgical Pathology (AJSP)
Archives of Pathology and Lab Medicine (Archives)
Human Pathology (Hum Path)
Modern Pathology (Mod Path)
Rosai, J: Ackerman’s Surgical Pathology (9th Ed); Mosby, 2004
Please refer to these primary references for more detailed discussions and photographs
Antibodies are often useful beyond their recommended expiration dates
Focus on what type of cells are staining (tumor cells, endothelial cells, stromal cells)
Note the number (percent) of cells staining, the intensity of staining and the pattern of staining (cytoplasmic, membranous, nuclear, dot like)
Pattern of immunoreactivity must follow the anatomic distribution of the antigen before it is called positive / immunoreactive
Repeating or performing additional tests may be important when reviewing slides of patients with prior diagnosis of cancer (AJSP 2002;26:1222)
Sources of error in interpretation are ectopic antigen expression, cross reactions, less specificity than thought
Recommended to obtain contemporaneous H&E section (AJSP 2007;31:1627)
Note: diagnosis should be based on H&E morphology, with confirmation by immunohistochemistry or molecular testing; it is dangerous to use immunohistochemistry alone to make the diagnosis
Note: combining results from different studies may be hazardous, as studies may use different antibodies and different standards of interpretation
Steps in immunohistochemistry:
1. pretreatment, often with microwaving of tissue in citrate buffer to unmask antigens hidden by formalin cross-links or other fixative
2. other agents for pretreatment (antigen retrieval) are pepsin, proteases, trypsin
3. apply primary antibody (monoclonal antibodies usually are more specific); antibody binds to antigens of interest
4. wash off excess primary antibody
5. add biotinylated anti-IgG antibody (secondary antibody), which binds to the primary antibody present
6. add avidin-biotin-peroxidase complex, which binds to secondary antibody
7. add 3, 3’ diaminobenzidine (DAB) as a chromagen (color changing reagent), with hematoxylin counterstaining
Other enzyme complexes besides avidin-biotin are horseradish peroxidase, alkaline phosphatase with naphthol phosphate and glucose oxidase with nitroblue tetrazolium
Other chromagens besides DAB are AEC (water soluble, sensitive to light)
Most important steps are selection of appropriate antibodies, correct interpretation, technical quality and integration of results into final diagnosis (AJSP 2002;26:873)
Common panels of immunohistochemistry stains
Epithelial markers: low molecular weight keratin (CAM 5.2), AE1-AE3 cytokeratin cocktail, CK7, CK20, CEA, EMA
Melanocytic markers: S100 (also a mesenchymal marker), HMB45, MelanA/Mart1
Mesenchymal markers: vimentin, Factor XIIIa, Factor VIII, CD31, CD34, HHF35, smooth muscle actin, desmin
Lymphoid markers: CD3, CD20, CD15, CD30, various others
Histiocytic markers: CD68, lysozyme, CD1a (Langerhans cells)
Neuroendocrine markers: neuron specific enolase, chromogranin, synaptophysin
Cell proliferation/apoptosis markers: Ki-67, bcl2
Recommended to interpret immunohistochemical stains in small needle core biopsy specimens based on the area with the greatest immunoreactivity (AJCP 2007;127:273)
Detects enzymatic activity in cytoplasm
Enzyme product unites with coupler, which produces localized color at site of enzyme activity
Fresh smears are preferred, especially for myeloperoxidase; if not possible, store unstained slides away from light
3 beta hydroxysteroid dehydrogenase
Critical enzyme in biosynthesis of all steroid hormones
Positive staining (normal): testicular Leydig cells
Negative staining: normal seminiferous tubules
Micro images: 3 beta-hydroxysteroid dehydrogenase immunohistology in adrenal gland
7-amino-actinomycin D (7 AAD)
DNA-binding, fluorescent dye is excited by 488 nm laser line commonly used in flow cytometry
Intact cells exclude 7 AAD; dead cells allow 7 AAD entry, which binds to DNA
Used in flow cytometry to reduce non-specific staining by eliminating 7 AAD positive cells (dead cells) from further analysis
14-3-3 sigma protein
Member of highly conserved family of acidic proteins
Phosphoserine binding protein that mediates G2/M arrest; also other cellular signaling pathways
May be a tumor suppressor, induced by DNA damage and p53
Cytoplasmic staining
Micro images: expression in normal and malignant tissue
Positive staining (normal): urothelium, prostate and breast periductal and periglandular cells, uterus (strong in squamous epithelium, weak in endometrial and endocervical glands)
Positive staining-tumors: bladder urothelial carcinoma (98%), cervical squamous cell carcinoma (67%), endometrial adenocarcinoma (57%), prostatic adenocarcinoma (55%), ovarian carcinoma (33%), testicular tumors (27%), breast carcinoma (23%), renal carcinoma (12%)
Negative staining: germinal cells of testis and ovary, kidney (sporadic expression in tubules)
References: Mod Path 2005;18:340
45M1
Recognizes peptide core of M1 gastric mucin antigen
Positive staining (normal): normal gastric epithelium
Positive staining (disease): intestinal metaplasia in Barrett’s esophagus, AJSP 2001;25:87
Negative staining: mature small intestinal goblet cells
A beta 42
42 amino acid protein; variant of APP
May be prone to forming plaques in Alzheimer’s
Deposited early in plaques; may be a seed for other plaques
abl
also called c-abl; gene at 9q34.1, named after abelson murine leukemia virus
Functions as a tyrosine kinase / signal transducer and a negative regulator of apoptosis
Overexpression causes resistance to apoptosis induction by Fas, ceramide or chemotherapy
Overexpressed in chronic myelogenous leukemia
Acid fast bacilli (AFB) - Stains chapter
last updated October 2008
Acid fast refers to microorganisms whose cell wall has a high lipid content of mycolic acids and long chain fatty acids (diagram), which causes them to bind and retain the complex basic dye carbol-fuchsin even after strong decolorization with acid-alcohol (thus “acid-fast”)
Acid fast organisms: Mycobacteria, Cryptosporidium parvum, Isospora and Cyclospora cysts, hooklets of cysticerci
Partially acid fast organisms: exhibit both acid fast and non acid fast bacilli and filaments in a single strain - nocardiae (Univ Texas Med Branch), Dietzia (Int J Syst Evol Microbiol 2006;56:1667), Rhodococcus (South Med J 1991;84:1217), Gordonia (Emerg Infect Dis 2000;6:382), Tsukamurella (J Med Case Reports 2008;2:207), rarely Mycobacterium peregrinum (J Clin Microbiol 2005;43:2015)
Recommended that laboratories standardize and optimize their particular processes (J Clin Pathol 2003;56:613)
Note: nucleic acid based tests can rapidly detect and speciate mycobacteria (Archives 2008;132:1333, Thorax 2008;63:317)
Acid-fast methods:
Ziehl-Neelsen (classic) - commonly used; bacteria stain bright red due to retention of carbol-fuchsin dye, against blue background due to methylene blue counterstain; procedure involves heat (procedure #1, #2)
Ziehl-Neelsen (modified bleach) - more sensitive than classic (Acta Cytol 2008;52:325)
Kinyoun - commonly used; uses more concentrated fuchsin dye and lipid solvent, but no heat; bacteria stain bright red against green background (procedure #1, #2)
Fite - used for detecting M. leprae (leprosy) and Rhodococcus (Diagn Cytopathol 2001;24:244); combines peanut/vegetable oil with xylene to minimize exposure of bacteria cell wall to organic solvents and protect precarious acid-fastness of organism (procedure #1, #2)
Ellis and Zabrowarny - excludes phenol; procedure (J Clin Pathol 1993;46:559)
Auramine-rhodamine - mixture of Auramine O and Rhodamine B dyes, auramine binds to mycolic acid in cell wall; detection requires a fluorescence microscope (mercury vapor lamp or LED), but is the most sensitive stain for mycobacteria (Hum Path 1984;15:1085) [nucleic acid methods are more sensitive but are not stains]; saves time in searching for microorganisms (Clin Infect Dis 2008;47:203); procedure
Water filters are recommended to reduce false positives due to nonTB mycobacteria (Appl Environ Microbiol 2007;73:6296)
In Mexico, nontuberculous mycobacteria cause superinfection of lipoid pneumonia (caused by aspiration), associated with malnourished infants (Fetal Pediatr Pathol 2006;25:107)
Acid fast bacilli (AFB) - Stains chapter (continued)
Micro images:
Cryptosporidium - oocysts-modified acid-fast #1; #2; stool specimen (Ziehl-Neelsen); oocysts-auramine-rhodamine stain
Mycobacterium tuberculosis - site
unknown (Ziehl-Neelsen); cervix; lung
(Ziehl-Neelsen); lung
(auramine), small
intestine #1 (method unknown); #2
Mycobacterium avium-complex - Ziehl-Neelsen;
bone marrow #1;
#2-M. kansasii;
breast (Ziehl-Neelsen); colon
(Ziehl-Neelsen); liver; lymph
node post bCG vaccination (Ziehl-Neelsen); spleen; stomach-modified
Fite stain
Mycobacterium leprae - liver-Fite stain
Nocardia - lung-Fite-Faraco Modified Acid Fast stain #1; #2; #3; #4
Rhodococcus - Kinyoun modified acid-fast stain of non-lysed sputum, AFB+ cocci can be seen in a macrophage
Other - Kayexalate particles at site of aspiration pneumonia (Ziehl-Neelsen with light counterstain)
Acid phosphatase
Enzyme histochemistry technique
Positive staining: osteoclasts
Enzyme cytochemistry: T-ALL (focal paranuclear), AML (variable)
Acridine Orange
Used for staining low numbers of bacteria; examine under ultraviolet light
Actin is globular protein found in all eukaryotic cells except nematode sperm
Highly conserved, differs by at most 20% between algae and humans
Monomeric subunit of microfilaments, one of 3 major components of cytoskeleton (also microtubules and intermediate filaments); also a component of thin filaments (part of contractile apparatus of muscle cells)
Mammals have at least 6 actin isoforms - two smooth muscle (alpha smooth muscle and gamma smooth muscle), two sarcomeric (alpha cardiac and alpha skeletal) and two nonmuscle (beta cytoplasmic and gamma cytoplasmic)
Muscle cells contain alpha and gamma smooth muscle actin, alpha cardiac and alpha skeletal actin
Nonmuscle cells contain beta and gamma cytoplasmic actin
Functions: muscle cells - contraction; all cells - forms part of cytoskeleton, associated with motility
Actin and myosin in muscle: drawing #1; #2; animation
References: Wikipedia
Actin, alpha cardiac type
There are two types of alpha sarcomeric/striated actin: cardiac type and skeletal muscle type; both are expressed in cardiac and skeletal muscle, but the proportions vary at different developmental periods (J Biol Chem 1994;269:12212) or with disease (Rapid Commun Mass Spectrom 2003;17:1467)
Mutations in cardiac type may cause dilated or hypertrophic cardiomyopathy (J Mol Cell Cardiol 2000;32:1687), atrial septal defects (Hum Mol Genet 2007 Oct 18 [Epub ahead of print])
Positive staining (normal): myocardium (adult and fetal), skeletal muscle (fetal), skeletal muscle (adult-muscle spindle myocytes), vascular smooth muscle (occasional)
Positive staining (disease): skeletal muscle (regenerating skeletal muscle cells [Differentiation 1996;60:245], Duchenne muscular dystrophy, degenerative atrophy), rhabdomyosacoma, Wilm’s tumor-rhabdomyomatous cells, occasional smooth muscle tumors
Negative staining (normal): skeletal muscle (adult, but muscle spindle myocytes are positive)
References: Virchows Arch 2006;449:175
Actin, alpha skeletal type
There are two types of alpha sarcomeric/striated actin: cardiac type and skeletal muscle type; both are expressed in cardiac and skeletal muscle, but the proportions vary at different developmental periods (J Biol Chem 1994;269:12212) or with disease (Rapid Commun Mass Spectrom 2003;17:1467)
Absence causes nemaline myopathy (Ann Neurol 2007;61:175)
Positive staining: rhabdomyosarcoma (but not commonly used, AJSP 1985;9:467)
Actin, alpha smooth muscle type
Also called smooth muscle actin, SMA; clone 1A4 or sm-1
Discovered in 1986 (J Cell Biol 1986;103:2787)
Antibodies to alpha smooth muscle actin do not detect the other actin isoforms
Reduced expression in brain blood vessels in Alzheimer patients (J Neuropathol Exp Neurol 2004;63:735)
No apparent deficiency in intestinal pseudoobstruction (J Clin Pathol 2004;57:1168)
Uses:
(a) identify smooth muscle cells and myofibroblasts in normal, reactive (Am J Respir Cell Mol Biol 1999;20:582) or neoplastic tissue (Am J Dermatopathol 2006;28:105)
(b) identify myoepithelial cells in normal, neoplastic or diseased breast, salivary glands or sweat glands; may be helpful to rule out invasion; may be particularly important in cytology specimens (Anticancer Res 2003;23:4175)
(c) identify pericytes, which are associated with mature microvessels and better prognosis in colorectal carcinoma (Oncology 2005;69:159)
(d) help distinguish pleuropulmonary desmoid tumors (SMA+) from solitary fibrous tumor (SMA-, Archives 2006;130:1503)
Note: in breast papillary lesions, p63 is a more sensitive and specific marker because smooth muscle actin also stains stromal cells (J Clin Pathol 2007;60:315)
Interpretation: membranous or cytoplasmic staining
Positive staining (normal): myoepithelial cells of breast (most but not all, Breast Cancer Res 2003;5:R151), salivary glands, sweat glands and tracheobronchial glands (J Histochem Cytochem 1988;36:659); myofibroblasts (except alveolar-J Histochem Cytochem 1992;40:1955 and some granulation tissue/scars-Lab Invest 1989;60:275, Int J Legal Med 1992;105:99), pericytes (J Histochem Cytochem 1989;37:315), smooth muscle, vascular smooth muscle; also chondrocytes (Folia Biol (Praha) 2006;52:167), choroidal non-vascular smooth muscle cells (J Anat 2005;207:381), decidual stromal cells (Hum Reprod 1999;14:1599), fibroblastic reticulum cells (J Cancer Res Clin Oncol 1981;101:149), glomus coccygeum (Archives 1999;123:905), hepatic stellate cells (Virchows Arch 1997;430:195), osteoblasts (J Orthop Res 2002;20:622)
Actin, alpha smooth muscle (continued)
Positive staining (disease): adenoid cystic carcinoma (Archives 1999;123:801), angiomyofibroblastoma (occasionally focal, Hum Path 1997;28:1046), angiomyolipoma, atypical teratoid/rhabdoid tumor (J Neurosurg 1996;85:56), collagenous spherulosis (Mod Path 2006;19:1351), endometrial stromal sarcoma (65%, Gynecol Oncol 2004;92:71), endometriosis-stroma (Pathol Int 2003;53:371), epithelial-myoepithelial carcinoma (AJSP 2007;31:44), epithelioid sarcoma-proximal type (33%, AJSP 1997;21:130), fibromatosis (56%, AJSP 2002;26:1296), fibroblastic reticulum cell tumor (AJSP 1998;22:1048), gastric carcinoma stromal cells (J Clin Pathol 2002;55:741), GIST (45%, AJSP 2002;26:1296), glomus tumor (Hum Path 1999;30:1259), granulosa cell tumors of ovary-adult (variable, Mod Path 1995;8:25), hemangiopericytoma (AJSP 2003;27:737), kidney-focal segmental glomerulosclerosis (Braz J Med Biol Res 2001;34:985), inflammatory myofibroblastic tumor (Ann Diagn Pathol 2001;5:335, AJSP 1992;16:896), leiomyoma, leiomyosarcoma, liposarcoma (focal in some cases, AJSP 2004;28:1257), melanoma-desmoplastic (Am J Dermatopathol 1999;21:537), mesothelioma-sarcomatoid (60%, Histopathology 2003;42:270), MFH (30%, J Clin Pathol 2003;56:666), myoepithelioma (57%, Hum Path 2004;35:14), myofibroblastoma (occasionally focal, Pathology 2005;37:144, AJSP 2001;25:1022), myofibroblastic sarcoma (Chin Med J (Engl) 2007;120:363), nodular fasciitis (Ann Diagn Pathol 2002;6:94), ossifying fibromyxoid tumor (some, J Laryngol Otol 1993;107:75), pancreatic stellate cells post-obstruction (J Surg Res 2003;114:6), plexiform fibrohistiocytic tumor (Histopathology 1991;19:503), pulmonary lymphangioleiomyomatosis (J Clin Pathol 1993;46:479), renal mixed epithelial and stromal tumor (Archives 2006;130:80), rhabdomyoma (focal/rare, Hum Path 1993;24:754, Hum Path 1993;24:608), rhabdomyosarcoma (botryoid type, Pediatr Dev Pathol 2005;8:427), spindle cell carcinoma (AJSP 2001;25:1009), synovial sarcoma (25%, Mod Path 2007;20:760)
Negative staining (normal): cardiac muscle (positive during development-J Cell Sci 2007;120:229), skeletal muscle (J Cell Biol 1985;100:807)
Negative staining (disease): carcinomas (usually), schwannoma, solitary fibrous tumor (Archives 2006;130:1503)
Micro images:
Normal: chondrocytes-ear; decidual stromal cells; eye-choroid and sclera
Breast: myoepithelial cells #1; #2 (fig C/G); adenoid cystic carcinoma (fig B) vs collagenous spherulosis (fig G); basal-like carcinoma (fig a); cellular fibroadenoma (fig a-black cytoplasmic staining) and phyllodes tumor (fig b); fibromatosis; hamartomas-myoid; leiomyoma; myoepithelial cell disruptions in normal and hyperplastic epithelium
Actin, alpha smooth muscle (continued)
Micro images (continued):
GI: colon-carcinosarcoma; colon-leiomyoma #1 (top); #2; colon-Peutz Jeghers polyp (fig 4); gastric carcinoma-diffuse type (fig A); gastric carcinoma-intestinal type (fig A); liver epithelioid angiomyolipoma; liver glomangioma (fig 5); small intestine, colon and cases of intestinal pseudoobstruction; various sites-inflammatory fibroid polyp
Lung: normal and early pulmonary hypertension; late pulmonary hypertension; lymphangioleiomyomatosis;
inflammatory myofibroblastic tumor: bone; gallbladder; pleura; salivary gland (fig 3b)
leiomyosarcoma: bladder leiomyosarcoma (fig C); cervix; esophagus #1 (fig b); #2; face; mandible (fig D); skin; thyroid
Other: bladder-PEComa; cardiac scar tissue; Crohn’s disease-obliterative muscularization; desmoid tumor of lung (fig D); eye-MFH of conjunctiva (top left); glomus coccygeum (fig d); glomus tumor-bone; heart from fetus with heart block; hemangiopericytoma-sinonasal; kidney-atypical epithelioid angiomyolipoma #1; #2 (fig 3B); kidney-focal segmental glomerulosclerosis; larynx-spindle cell carcinoma (fig 1e); lip-angiomyolipoma (fig 2); melanoma-desmoplastic (fig 7); myofibroblastic sarcoma (left: smooth muscle actin, right: muscle specific actin); myofibroblastoma of lymph node-interstitial cells are SMA+; placenta accreta (fig 3); plexiform fibrohistiocytic tumor (staining of tumor cells around nests); pleomorphic sarcoma/MFH #1; #2 (fig B); salivary gland duct carcinoma-myoepithelial layer rules out invasion; salivary gland sialometaplasia in parotid node; submandibular gland-adenoid cystic carcinoma
Actin, muscle specific - Stains chapter
last updated October 2008
Also called HHF35, MSA
Recognizes all alpha actins (skeletal, smooth, cardiac) and gamma smooth muscle actin; not beta cytoplasmic or gamma cytoplasmic
Recognizes actin expressed in all cells with muscle differentiation (cardiac, smooth and skeletal muscle), myoepithelial cells, myofibroblasts, pericytes and myogenic tumors
Discovered in 1987 (Am J Pathol 1987;126:51)
Uses:
(a) identify skeletal muscle (Tumori 2007;93:198, J Cutan Pathol 2007;34:352) and smooth muscle cells (Eur Respir J 2001;17:316) in normal tissue or various disease entities
(b) classify tumors of smooth or skeletal muscle, pericytes, myofibroblasts or with myoepithelial cells
(c) differentiate leiomyosarcoma (MSA+, keratin-) from spindle cell carcinoma (MSA-, keratin+, Am J Otolaryngol 2005;26:201)
Positive staining (normal): cardiac muscle, decidua, myoepithelial cells (although calponin and vimentin may be better, Braz Dent J 2007;18:192), myofibroblasts, pericytes, skeletal muscle, smooth muscle, vascular smooth muscle
Positive staining (disease): adenoid cystic carcinoma-myoepithelial component (J Oral Maxillofac Surg 2006;64:415), angiomyolipoma, cardiac rhabdomyoma, chondroblastoma (35%, Hum Path 1997;28:316), endometriosis-smooth muscle (Hum Reprod 2000;15:767), fibromatosis (Acta Cytol 1991;35:403), glioblastoma multiforme (occasional), glomus tumor (Hum Path 1999;30:1259), hemangiopericytoma (Head Neck 2005;27:124, AJSP 2003;27:737), inflammatory myofibroblastic tumor (Mod Path 2001;14:784), leiomyoma (Int J Gynecol Pathol 1995;14:134), leiomyosarcoma (80-100%, J Pak Med Assoc 2005;55:138, APMIS 1997;105:793), MFH (30%, J Clin Pathol 2003;56:666), myoepithelioma, myofibroblastic sarcoma (Chin Med J (Engl) 2007;120:363), myofibroblastoma (variable), osteosarcoma (AJCP 2000;113:663), pleomorphic adenoma (Hum Path 1991;22:1206, rhabdomyosarcoma (but MyoD1 and myogenin are more specific/sensitive, AJSP 2006;30:962), solitary fibrous tumor (variable staining, Mod Path 1997;10:443)
Negative staining (disease): angiomyofibroblastoma (Pathol Int 1995;45:487), mesothelioma-epithelioid (AJSP 2006;30:463)
Micro images: angiomyolipoma of lip (fig 3); cardiac rhabdomyoma-highlights spider cells and cross striations (arrowheads); endometriosis-ovary; endometriosis-peritoneal; endometriosis-rectovaginal; hemangioma of heart-outlines vascular channels; leiomyosarcoma-cervix; myoepithelioma-breast; myofibroblastic sarcoma (left: smooth muscle actin, right: muscle specific actin); pleomorphic sarcoma (fig C); prostate-sclerosing adenosis; rhabdomyosarcoma-vagina (botyroides)
References: AJCP 1991;96:32
Adhesion molecules
Overexpressed in chronic inflammatory diseases, including synovium in rheumatoid arthritis
AE1, AE3
AF-4
Gene at 4q21
Translocations with MLL via t(4;11)(q21;q23 ) in acute leukemia
AF-9
Gene at 9p22
Translocations with MLL via t(9;11)(p22;q23 ) in acute leukemia
AIB1
Also called SRC3, TRAM1
Member of steroid receptor coactivator 1 family at 20q12
Involved in cell proliferation, migration and differentiation
References: Hum Path 2005;36:777 (colorectal carcinoma)
Albumin
In-situ hybridization may be specific for hepatocellular carcinoma or hepatoid areas of combined hepatocellular-cholangiocarcinoma (AJSP 2002;26:989)
Alcian blue
Detects acidic mucins
At pH 1.0, detects highly acidic mucins
Micro images: nodular mucinosis (fig 3A), removal of staining after hyaluronidase (3B)
Alcian blue/high iron diamine
Positive staining: Sulfomucins - brown, sialomucins - blue
Alk (see also NPM-ALK)
Anaplastic lymphoma kinase gene at 2p23; Also called CD246
Membrane spanning tyrosine kinase receptor, member of insulin receptor family
Ligand is growth factor pleiotrophin
3' end contains catalytic domain of tyrosine kinase
t(2;5) associated with T cell anaplastic lymphoma via fusion of ALK and nucleophosmin protein
Has important role in brain development
ALK+ primary anaplastic large cell lymphomas have favorable prognostic significance
ALK- cases of primary anaplastic large cell lymphoma are associated with trisomy 2 (Mod Path 2005;18:235)
Positive staining (normal): normal small intestine, T cells; weakly positive in brain, colon, prostate
Positive staining (disease): T or null cell anaplastic lymphomas (some), inflammatory myofibroblastic tumor (AJSP 2001;25:1364, AJSP 2001;25:761)
Negative staining: fibromatosis, GIST, nodular fasciitis, normal lymphoid tissue
Alkaline phosphatase
Membrane bound glycoproteins, with hepatic, osseous, renal and placental isoenzymes
See PLAP
Positive staining (normal): osteoblasts
Positive staining (disease): mononuclear stromal cells from giant cell tumor of bone and soft tissue (Hum Path 2005;36:945)
ALL1
Gene at 11q23 also called MLL (mixed lineage leukemia), HRX, Htrx (from Drosophila trithorax protein)
Affected by self-fusion translocation of t(11;11)(q23;q23)
Self fusion causes the gene to be dominant negative by fusing with other genes
Trisomy causes loss of function of the gene, leading to B cells with both lymphoid and myeloid phenotypes
Self fusion involves “Alu” sequences, which are conserved elements of repetitive DNA in non-protein coding region
There are 1 million copies of Alu sequences in human genome, each about 300 base pairs in length
Alu mediated recombination causes partial duplication of the ALL1 gene
ALL1 tumors: usually CD10 negative, CD19+, with lymphoid and myeloid markers
Bone marrow transplantation recommended in childhood ALL with t(4;11)(q23;q23) due to otherwise poor prognosis
90% of all cases with ALL abnormalities are t(4;11), t(9;11), t(11;19)
Accounts for 5-10% of acute leukemias, usually M4 or M5
Present in 60% of infants < 1 year with ALL
Abnormal expression in 10% of ALL, 6% of AML, 80% of secondary leukemia after topoisomerase II inhibitor treatment
Alpha
Part of t(6;11)(p21;q12); TFEB and Alpha; renal neoplasm of children and young adults (AJSP 2005;29:230)
Gene is at 11q12; lacks introns or splice signals; does not code for a functioning protein
Can detect using DNA PCR as an alternative to RT-PCR since Alpha lacks splice signals
Nuclear stain
Alpha-1-antichymotrypsin
Acute phase plasma protease inhibitor, mainly produced by liver
Homologous to alpha-1-antitrypsin
Positive staining: histiocytes, reticulum cells
Micro images: pancreatoblastoma: C - positive staining
Alpha-1-antitrypsin
last updated October 2008
Enzyme that inhibits proteases, particularly elastase (which digests lung tissue), which is secreted by neutrophils during inflammation Genetic deficiency (due to folding errors, IUBMB Life 2008 Sep 10 [Epub ahead of print]), causes emphysema (Orphanet J Rare Dis 2008; 3:16), cirrhosis (Am J Gastroenterol 2008;103:2136), panniculitis (Dermatol Clin 2008;26:447)
Homologous to alpha-1-antichymotrypsin
Positive staining (normal): histiocytes, reticulum cells, gallbladder, hepatocytes, small intestinal enterocytes (J Clin Invest 1993;92:2022)
Positive staining (disease): various sites-angiosarcoma (hyaline globules), granular cell tumor (J Oral Pathol Med 2000;29:284, Mod Path 1996;9:888), histiocytic lymphoma, MFH, pleomorphic adenoma (epithelium), Rosai-Dorfman disease (focal); bile duct-adenoma-(cytoplasmic inclusions, Int J Surg Pathol 2008;16:218), bladder-yolk sac tumor of urachus; bone-giant cell tumor, cervix-decidual reaction; eye-oncocytoma of conjunctiiva; kidney-renal cell carcinoma-clear cell type; liver- alpha-1-antitrypsin deficiency (cytoplasmic inclusions), focal nodular hyperplasia, hepatoblastoma (40%, Appl Immunohistochem Mol Morphol 2008;16:140), hepatocellular adenoma (cytoplasmic globules), hepatocellular carcinoma, undifferentiated embryonal sarcoma; lung-bronchioloalveolar carcinoma (Clara cells in non-mucinous types); ovary-endodermal teratoma, MMMT and yolk sac tumor (hyaline droplets, Hum Path 1982;13:930); pancreas-cystic fibrosis (mucous globules), neuroendocrine tumor and solid pseudopapillary tumor (AJSP 2000;24:1361); skin-atypical fibroxanthoma; testis-papillary cystadenoma, Sertoli cell tumor and yolk sac tumor (hyaline globules); thyroid-papillary thyroid carcinoma (AJSP 1996;20:956)
Micro images: liver-alpha-1-antitrypsin deficiency; liver-undifferentiated embryonal sarcoma; lymph node-Kikuchi’s lymphadenitis; pancreas-solid pseudopapillary tumor #1; #2; #3; pancreatoblastoma: fig B; peripheral giant cell granuloma
References: Wikipedia
Major plasma protein of early fetus; present in fetal gut, liver and yolk sac (Wikipedia)
Uses as serum marker:
Elevated in maternal serum or amniotic fluid (> 2.5 multiples of median at a specified gestational age) if fetal developmental anomalies; also a serum tumor marker elevated in patients with hepatoblastoma (eMedicine), hepatocellular carcinoma, hepatoid adenocarcinoma, testicular cancer (other than pure seminoma), yolk sac tumor; high levels are poor prognostic marker for hepatocellular carcinoma (J Gastroenterol Hepatol 2008;23:e189)
Uses as immunostain:
Somewhat sensitive and specific for hepatocellular carcinoma, hepatoid adenocarcinoma, germ cell tumors, particularly yolk sac
Positive staining (disease): various sites-embryonal carcinoma, hepatoid adenocarcinoma (J Clin Pathol 1996;49:420, Int J Gynecol Cancer 2007;17:1150), yolk sac tumor, occasionally extrahepatic carcinomas (Acta Cytol 2003;47:799); liver-hepatoblastoma, hepatocellular carcinoma (60% -Mod Path 1997;10:686, AJSP 2002;26:978); pancreas-acinar cell carcinoma (some, Anticancer Res 2005;25:1671), pancreatoblastoma (up to 68%, JOP 2007;8:55)
Micro images: bladder-yolk sac tumor of urachus (fig D); extragonal germ cell tumor-yolk sac component (fig B); liver-adult hepatic blastoma (fig B); testis-yolk sac component of mixed germ cell tumor
Alpha-lactalbumin
Major protein of human milk
Specific to breast tissue (normal, malignant, fibrocystic) and hydradenoma papilliferum of vulva
Alpha-naphthyl acetate / alpha-naphthyl butyrate
See Non specific esterase
Alpha-naphthyl chloroacetate esterase
Note: staining is opposite of alpha-naphthyl acetate
Positive staining: granulocytes
Negative staining: monocytes and lymphocytes
AMACR
Alpha MethylAcyl Coenzyme A Racemase; also called P504S
Identified from prostate adenocarcinoma by cDNA library subtraction coupled with high throughput microarray screening of human prostatic tissue
Also expressed in colorectal adenocarcinoma and other malignancies, but not in normal appearing small and large intestinal mucosa
A mitochondrial and peroxisomal enzyme involved in beta-oxidation of dietary branched-chain fatty acids and fatty acid derivatives (including bile acid intermediates)
Sensitive (82-95%) and relatively specific for prostate carcinoma vs. benign prostate (AJSP 2001;25:1397, AJSP 2002;26:1588)
In prostate carcinoma, is strongly positive, usually diffuse, regardless of Gleason grade
Relatively specific - benign prostate is usually negative or only focal/weakly positive; however partial atrophy and crowded benign glands may be positive (AJSP 2005;29:874)
Most specific if circumferential luminal to subluminal and diffuse cytoplasmic staining
Uses: identify small foci of prostatic adenocarcinoma, in conjunction with 34 beta E12 or p63 (AJSP 2002;26:1169), may identify a subset of AAH with a premalignant potential (AJSP 2002;26:921)
Positive staining (disease): prostatic adenocarcinoma and high grade PIN; partial prostatic atrophy and crowded benign prostatic glands may be positive (AJSP 2005;29:874); also overexpressed in lymphomas and cervical, colorectal adenocarcinoma (69-83%, AJSP 2005;29:890), breast, gastric, liver, ovarian, renal cell carcinomas (AJSP 2002;26:926), urothelial carcinoma (30%), primary (65%) and secondary (from colorectum) bladder adenocarcinomas (Mod Path 2005;18:1217)
Negative staining: benign prostate (usually, see exceptions under positive staining), atypical adenomatous hyperplasia (usually, 10% are positive, AJSP 2002;26:921); small intestinal adenocarcinoma (usually, only 4-6% are positive, AJSP 2005;29:890)
Micro images: fig 3a: primary bladder adenocarcinoma (diffusely+) vs. 3b: secondary from colorectum (focal+)
AMF
Autocrine motility factor
Induces the directed and random migration of AMF producing tumor cells
Expression of its receptor correlates with stage and recurrence in bladder carcinoma
Expression of its receptor is associated with down regulation of E-cadherin
AMH
Anti-Mullerian Hormone
High serum levels associated with granulosa cell tumors of ovary and testis
Positive staining (normal): prepubertal Sertoli cells
Negative staining: pubertal Sertoli cells
AML1
Gene at 21q22 is DNA binding component of AML1/CBF beta transcription factor complex, most frequent target of translocations in AML via t(8;21) [AML1-ETO]; t(12;21); t(3;21) [AML1-EVI1]
Fusion products (below) suppress normal AML1 mediated transactivating activity
Normal AML1 required to establish fetal liver-derived definitive hematopoiesis (stem cells to definitive hematopoietic elements)
Androgen receptor
Interpretation: nuclear stain
Positive staining (normal): skin apocrine and sebaceous glands
Positive staining (disease): high grade DCIS, high grade invasive breast carcinoma, mammary and extramammary Paget’s disease (Mod Path 2005;18:1283)
Micro images: androgen receptor+ vulvar (fig 1c) and breast (fig 1d) Paget’s disease
AP-1
Activator protein 1, a transcription factor complex composed of proteins that bind to AP-1 DNA recognition elements, which induces expression of genes controlling cell growth and apoptosis
Includes 4 subfamilies Jun, Fos, Maf and ATF, which function as a complex of homodimers and heterodimers
AP-2
Family of 5 transcription factors, all homologous 50 kDa proteins: AP-2alpha, AP-2beta, AP-2gamma, AP-2delta and AP-2epsilon, encoded by separate genes
These transcription factors homo- or heterodimerize and transactivate their target genes by binding to GC-rich sequences in their promoter regions
AP-2alpha represent CK18+ breast glandular epithelial cells and AP-2gamma represent smooth muscle actin+ myoepithelial cells in non-neoplastic breast tissue and DCIS
have distinct spatial distribution in non-neoplastic breast epithelia
References: Mod Path 2005;18:431
APC
Adenomatous polyposis coli gene on 5q21, tumor suppressor gene, autosomal dominant
Important for familial adenomatous polyposis and Gardner syndromes
Binds to (a) microtubule bundles and promotes cell migration and adhesion, (b) beta-catenin (cytoskeletal protein) in a cellular adhesion complex including E-cadherin, part of Wnt signaling pathway
Beta-catenin is also bound to a T cell factor-lymphoid enhancer factor (Tcf-Lef), which activates other genes, stimulates cell proliferation and inhibits apoptosis
APC accelerates the proteasome-mediated degradation of beta-catenin, which reduces its role as a transactivating factor for the Tcf-Lef pathway
Mutations in APC produce elevated levels of Tcf4-beta-catenin, which stimulates a transcriptional response that initiates polyp formation and eventually malignant growth
APC is considered a gatekeeper gene since it directs activity downstream of different pathways
Colon: mutations play critical role in tumorigenesis (mutations in APC or beta-catenin present in 90% of colon cancers)
API2
Member of the IAP (inhibitor of apoptosis) gene family; essential for suppression of apoptosis
API2-MALT1
Fusion protein associated with MALT lymphoma (50%); rarely with diffuse large B cell lymphoma
Due to t(11;18)(q21;q21) - API2 and MALT1
May lead to increased inhibition of apoptosis, helping MALT lymphoma cells to survive
References: Mod Path 2003;16:1232 (colorectal lymphoma), Hum Path 2003;34:1212 (diffuse large B cell lymphoma)
Apolipoprotein D (apoD)
Member of lipocalin superfamily of proteins involved in transport of cholesterol, steroid hormones and other small hydrophobic molecules
Correlates with cell cycle inhibition in various situations including cellular senescence
High levels in fibrocystic breast disease and HDL, but produced by almost all tissues in body
Expression upregulated in nonneoplastic regenerating peripheral nerve compared to normal, then downregulated during transformation to MPNST (Hum Path 2005;36:987)
Argentaffin
Argentaffin cells/tissues contains a substance (such as catecholamines, indolamines) that reduces silver and other metallic salts to metallic silver, staining brown or black
Argentaffin stains are: Fontana-Masson, Schmorl's, Autofluorescence, diazonium salt
Argyrophilic
Argyrophilic cells/tissues contain a substance that reduces silver solution to metallic silver after exposure to an extraneous reducing agent, such as hydroquinone or formalin
Argyrophilic stains: Grimelius (with Bouin's fixative), Churukian-Schenk’s modification, Pascual's
ARP
Arginine Rich Protein, 3p21
Deleted or mutated in 50% of sporadic renal cell carcinomas
ARPP
a protein including an Ankyrin Repeat PEST motif and Proline-rich region
Homologous to cardiac ankyrin-repeat protein and diabetes-related ankyrin repeat protein
May act as molecular link between myofibrillar stretch-induced signaling pathway and muscle gene expression
Expressed exclusively in striated muscle (in normal human tissue), within I band of sarcomere
Positive staining (disease): rhabdomyosarcoma (89%), epithelioid sarcoma (60%, focal/weak or strong), Ewing’s sarcoma (20%, focal/weak), malignant fibrous histiocytoma (10%, focal/weak), synovial sarcoma (10%, focal/weak)
Interpretation: definitive cytoplasmic staining is required (nuclear staining is nonspecific)
References: Hum Path 2005;36:620
Asbestos
Special type of long-thin silica crystal, usually from mineral group chrysotile
Highly fibrogenic in tissue
Called ferruginous bodies in tissue - fibers coated with protein-iron-calcium matrix, giving them a shish-kebab appearance; highlighted with iron stain
Image: Asbestos body, unstained
Image: Asbestos bodies, iron stain
ATM
Ataxia telangiectasia mutation
Mutations cause suboptimal induction of p53 dependent signaling after exposure to DNA damaging agents, which causes an increase in mitotic recombination
Auramine stain
Autocrine motility factor
Produced by neoplasms; induces in vitro migration of tumor cells
Autotaxin
Motility factor in melanoma cells
Last revised 29 March 2009
Definition: monoclonal antibody that recognizes tumor-associated glyocoprotein 72 (TAG-72), a mucin-like sugar and protein complex on the surface of many cancer cells
Antibody is directed against the Sialyl-Tn blood group antigen
Intrepretation: cytoplasmic staining
Uses:
(1) distinguish pulmonary adenocarcinoma (positive) from mesothelioma (negative) as part of a panel (Diag Cytopathol 1997;17:115)
(2) distinguish carcinoma in cytology specimens (positive) from benign effusions (usually negative, but may have focal staining, J Clin Pathol 1990; 43:1026, Acta Cytol 1987;31:537, Diag Cytopathol 2007;35:300)
(3) confirm diagnosis of breast apocrine carcinoma (APMIS 2006;114:712)
Positive staining (normal tissue): colonic mucosa (Hum Pathol 1989;20:994), endometrium-secretory, endometriosis (J Clin Endocrinol Metab 1993;76:1075), gastric/duodenal goblet cells-coarsely granular, gastric/duodenal epithelium-finely granular (Diagn Cytopathol 2005;33:381)
Positive staining (malignancies): angiosarcoma-epithelioid, breast apocrine carcinoma (92%), breast ductal carcinoma, colonic adenocarcinoma, endometrial carcinoma, esophageal squamous cell carcinoma, lung adenocarcinoma, ovarian serous tumors and implants, pancreatic ductal adenocarcinoma and intraductal oncocytic papillary neoplasm, prostatic adenocarcinoma, salivary gland carcinoma including duct carcinoma, mucoepidermoid carcinoma (Laryngoscope 1994;104:304) and malignant mixed tumor; testicular ovarian surface epithelial-like tumor, testicular serous papillary carcinoma, vulvar Paget’s disease
Negative staining (normal tissue): mesothelial cells, most benign cells except colon, duodenum, endometrium, gastric
Negative staining (disease): adrenocortical adenoma, adrenocortical carcinoma, anaplastic meningioma, lung small cell carcinoma, mesothelial cell inclusions in lymph nodes, mesothelial cysts in the kidney, mesothelioma, ovarian adnexal tumor of probable wolffian origin, ovarian primary retroperitoneal mucinous cystadenoma, ovarian small cell carcinoma-hypercalcemic type
Micro images: bronchioalveolar carcinoma of lung: A-H&E, B-cytoplasmic staining for CEA, C-cytoplasmic staining for B72.3
BAG1
Also called RAP46
Expressed by estrogen receptor positive breast cancers
Basement membrane
Composed of type IV collagen and laminin
BAT-26
Highly sensitive to microsatellite instability in colorectal carcinomas
Bauhinia purpurea (BPA)
Positive staining (normal): granulocytes, macrophages, germinal center lymphocytes
Positive staining (disease): Reed-Sternberg cells
bax
Member of bcl2 family; has pro-apoptotic activity
An increase in the ratio of bax to bcl2 promotes cellular apoptosis
Promotes apoptosis by either forming homodimers or binding with and inhibiting bcl2
BB4
See CD138 in the CD Markers chapter
B-CAM
B cell surface adhesion molecule at 19q13.2-13.3
Forms the Lutheran blood group gene by alternative splicing
Overexpressed in ovarian carcinoma
bcl1
See cyclin D1
bcl2
“b cell lymphoma #2”
Proto-oncogene at 18q21.3; encodes 25 kDa protein mainly localized to inner mitochondrial membrane; also endoplasmic reticulum and nuclear envelope
May participate in ion channel formation and alteration of membrane permeability necessary for initiation of apoptosis
Prevents cells from undergoing apoptosis
Bax homodimers normally cause apoptosis and non phosphorylated bcl2 inhibits apoptosis; bax can bind to and inhibit non-phosphorylated bcl2, promoting apoptosis
Has 2 conserved motifs (BH1, BH2) for binding to bax
Promoter interacts with Epstein-Barr virus latent membrane protein-1
May maintain memory B cells, plasma cells and neurons by prolonging life span without cell division
Overexpression causes B cells with increased life span
Uses:
Diffuse large cell lymphoma: adverse prognostic factor in some studies (Mod Path 2005;18:1113)
Follicular lymphoma: usually overexpressed due to t(14,18)(q32;q21) which brings bcl2 gene adjacent to immunoglobulin heavy chain (IgH) gene, causing overexpression of bcl2
Colorectal adenomas/carcinomas: overexpressed
Myelodysplastic syndrome: increased expression associated with progression
Uses: distinguish follicular hyperplasia of lymph node (germinal centers are bcl2 negative) and follicular lymphoma (germinal centers are bcl2 positive), but also positive in other lymphomas; to detect immature enteric ganglion cells in pediatric intestinal pseudo-obstruction (AJSP 2005;29:1017)
Positive staining (normal): small B lymphocytes in mantle zone and cells within T cell areas, medullary cells in thymus; immature (but not mature) small ganglion cells
Positive staining (disease): follicular lymphoma (germinal centers stain also), other lymphomas
Micro images: bcl2+ stromal cells in benign phyllodes tumor of breast
bcl3
Located at 14q32, part of t(14;v)(q32;v)
bcl6
Located at 3q27
Transcription factor normally expressed in germinal centers and in 5-15% of intrafollicular CD4+ T cells
Involved in cell proliferation and differentiation; selectively expressed by germinal center cells
Positive staining (normal): germinal centers of lymph nodes
Positive staining (disease): 30-80% of large cell lymphomas, 6-10% of follicular lymphomas
bcl-X
bcl2 like protein
Has 2 transcripts which either induce (bcl-Xs) or protect (bcl-Xl) against apoptosis
Thus, factors involved in RNA splicing may regulate apoptosis by differential splicing
bcl-XL
Longer transcript of bcl-X
Protects cells from apoptosis
bcl-Xs
Shorter transcript of bcl-X
Induces apoptosis
bcr
Gene present at 22q11 - breakpoint cluster region
bcr-abl
Protein fusion product formed by t(9;22)(q34;q11), called the Philadelphia chromosome
Either p210 or p185 hybrid proteins
p210 formed by bcr from 5' to b2/b3 of M (major)-bcr joined to second exon of c-abl (between IA and IB); has constitutive tyrosine kinase activity; associated with chronic myelogenous leukemia
p185 formed by bcr from 5' to m (minor)-bcr; more potent tyrosine kinase than p210; associated with ALL or AML
abl overexpression causes resistance to apoptosis induced by Fas, ceramide or chemotherapy
Found in 25% adult ALL, 5% pediatric ALL; 95%+ of patients with CML
Poor prognostic factor in pediatric ALL
BDCA-2
Specific marker for plasmacytic dendritic cells, present in CD4+ CD56+ hematodermic tumors (Hum Path 2005;36:1020)
Ber-EP4
Antibody to cell membrane glycoproteins; does not react with cytokeratin
Use: 100% sensitive, 91% specific for lung adenocarcinoma vs. mesothelioma; strong membrane staining; recommended threshold of 2% of cells with lateral membrane staining to call positive, AJSP 2001;25:43
Positive staining (normal): non-neoplastic epithelial cells
Positive staining (disease): lung adenocarcinomas; mammary Paget's disease, trichoepithelioma, dermatofibroma, basal cell carcinoma, carcinomas
Negative staining: non-basal layers of squamous epithelium
Beta-2-microglobulin
Forms light chain of HLA molecule
Present on surface of all nucleated cells
Increased levels in multiple myeloma
Beta 2 microglobulin amyloidosis is related to renal dialysis, increasing with duration of therapy and patient age
Gene is also called CTNNB1
Physiology: cytoplasmic protein normally adjacent to cell membrane, where it interacts with cytoplasmic domains of E-cadherin; E-cadherin and beta-catenin complex is connected to cytoskeletal actin by alpha-catenin; thus beta-catenin stabilizes E-cadherin, and participates in cell-cell adhesion mediated by E-cadherin
Important regulator of cell growth
Beta-catenin and T cell factor (Tcf) are also distal components of the highly conserved Wnt pathway that govern cell fate and proliferation in lower organisms; binds to APC; also binds to a T cell factor-lymphoid enhancer factor (Tcf-Lef), which activates other genes, stimulates cell proliferation and inhibits apoptosis; APC accelerates the proteasome-mediated degradation of beta-catenin, which reduces its role as a transactivating factor for the Tcf-Lef pathway
Mutations: mutations in APC produce elevated levels of Tcf4-beta-catenin, which stimulates a transcriptional response that initiates polyp formation and eventually malignant growth; mutations in beta-catenin itself can cause its activation
Colon: plays critical role in tumorigenesis (mutations in APC or beta-catenin present in 90% of colon cancers)
Uterus: endometrioid endometrial carcinoma is associated with beta-catenin mutations
Beta-catenin (continued)
Interpretation: nuclear staining is significant in fibroblasts, nuclear or cytoplasmic staining is significant in epithelial cells
Uses:
(1) distinguish mesenteric fibromatosis (positive with nuclear staining due to mutations in APC/beta-catenin pathway causing nuclear accumulation) from GIST tumors (negative) and sclerosing mesenteritis (negative, AJSP 2002; 26:1296)
(2) distinguish deep fibromatoses (diffuse or rarely focal nuclear staining) from low grade fibromyxoid sarcoma and other myofibroblastic or fibroblastic tumors/sarcomas (negative for nuclear staining, AJSP 2005;29:653)
Positive staining (normal): fibroblasts and endothelial cells (cytoplasmic-membranous staining)
Positive staining (disease): desmoid-type fibromatosis, solitary fibrous tumors (nuclear staining in 33%, remainder had membranous or membranous/cytoplasmic staining, Archives 2005;129:776); endometrioid carcinoma of endometrium and ovary, particularly squamous morules (Hum Path 2005;36:605)
Negative staining: GIST, sclerosing mesenteritis, low grade fibromyxoid sarcoma, myofibroblastic or fibroblastic tumors
Micro images: patterns of staining in solitary fibrous tumor; highly malignant adult hepatic blastoma - fig A: ferritin; B: alpha-fetoprotein; C: HepPar1; D: CK8; E: p53; F: beta-catenin; cytoplasmic and nuclear staining in desmoplastic fibroma
Beta-tubulin, class III
Marker for high-grade neuroendocrine pulmonary tumors (one study), other neuronal and neuroblastic tumors (medulloblastomas, retinoblastoma, neuroblastomas [olfactory, sympathetic], pheochromocytomas)
BG8
Click here
Bielschovsky
Highlights neurofibrillary tangles
Biotin
Interpretation: H&E shows optically clear nuclei or biotin-rich intranuclear inclusions; presence of biotin may cause false positive staining with avidin-peroxidase method
Positive staining (normal): pregnancy-related endometrium
Positive staining (disease): granulosa cell tumor-like variant of endometrioid carcinoma of ovary (Archives 2005;129:1288); also endometriotic cysts, morule-forming endometrioid carcinoma
Micro images: granulosa cell tumor-like variant of endometrioid carcinoma of ovary (figure 2C)
Blood group antigens (A, B, H)
Glycolipids in cell membranes of RBCs and epithelial cells
BLR-1
Putative chemokine receptor, coupled to G proteins, involved in B cell migration and localization within
specific autonomic compartments
BLR-1 mutant mice have no inguinal lymph nodes, no/reduced Peyer’s patches, reduced splenic follicles
BMP
Bone Morphogenetic Proteins
Members of transforming growth factor-beta (TGF-beta) superfamily (20 types cloned through October 2005)
Used for intercellular signals including cell growth and differentiation
Ubiquitous in embryonic development; also involved in apoptosis
Blocking their activity in chickens leads to duck feet
Deletion causes lack of mesoderm development, lack of sperm development, eye/kidney deformities, misshapen feet
Overexpression associated with fibrodysplasia ossificans progressiva, various bone and soft tissue sarcomas
Colonic adenocarcinoma: BMP5 and BMP6 prominent in cytoplasm of tumor cells, BMP2 and BMP4 strongly expressed in surrounding mesenchymal cells (Archives 2005;129:1347)
BMP2
Potent inducer of osteoblastic differentiation;
BMP4
Bone Morphogenic Protein 4
Powerful signaling protein, made by lymphocytes
Potent inducer of osteoblastic differentiation; helps developing embryo build its skeleton
Abnormalities cause fibrodysplasia ossificans progressiva (FOP), in which the slightest injury to tendons, ligaments or muscles causes severe inflammation and formation of cartilage or bone at site of injury
BRAF
Mutations in 36-69% of cases of papillary thyroid carcinoma (PTC)
Type of mutation associated with PTC histology: BRAFV600E-conventional papillary thyroid carcinoma and variants; BRAFK601E or no BRAFV600E-follicular variant of papillary thyroid carcinoma; BRAFtriplet deletion[ BRAFVK600-1E]-solid growth pattern (Hum Path 2005;36:694)
BRCA1
Tumor suppressor gene at 17q21; 220 kDa nuclear phosphoprotein, 1863 amino acids, 7.8 kb mRNA
Interacts with RAD51; may facilitate homologous recombination in bypass of stalled replication forks
Loss of functional BRCA1 or BRCA2 leads to activation of p53, causing cell cycle arrest or apoptosis; if p53 if inactivated, proliferation results in progressive accumulation of DNA damage and increased frequency of malignancy
Overexpression suppresses estrogen receptor transactivation
185delAG and 5382insC are common in Ashkenazi Jews
BRCA1 and BRCA2 mutations in Ashkenazi Jews have 2% prevalence vs. 0.1% of rest of population
Breast: normally expressed at puberty and pregnancy; interacts with cyclin dependent kinases; inhibits tumor growth in cell culture
Accounts for 5% (age <40 years) to 1% (age 50-70 years) of breast cancer cases in general population
Patients with BRCA1 or BRCA2 mutation have a 35%-80% lifetime risk of breast cancer by age 70; usually high grade, aneuploid, with basal / myoepithelial phenotype (P-cadherin+, EDGF receptor+, ER-, HER2-)
Higher risk with 300 T>G mutation
However, BRCA1 or BRCA2 mutation is also associated with medullary carcinoma of breast (more favorable prognosis)
Colon: relative risk of 4.0 for adenocarcinoma
Ovary: 30-60% lifetime risk of adenocarcinoma in women with mutations; usually associated with serous cystadenocarcinoma; often younger age and high stage; BRCA mutations cause 90% of hereditary cases of ovarian carcinomas, which account for 10% of all ovarian carcinomas
Prostate: relative risk of 3.0 for adenocarcinoma
Diagrams: normal and abnormal function; inactivation of BRCA1
References: OMIM 113705, Mod Path 2005;18:1305, Hum Path 2005;36:861 (hereditary ovarian cancer)
BRCA2
Tumor suppressor gene at 13q12-13
Interacts with RAD51; may facilitate homologous recombination in bypass of stalled replication forks
Loss of functional BRCA1 or BRCA2 leads to activation of p53, causing cell cycle arrest or apoptosis; if p53 if inactivated, proliferation results in progressive accumulation of DNA damage and increased frequency of malignancy
6174delT in BRCA2common in Ashkenazi Jews
BRCA1 and BRCA2 mutations in Ashkenazi Jews have 2% prevalence vs. 0.1% of rest of population
Breast: patients with BRCA1 or BRCA2 mutation have a 35%-80% lifetime risk of breast cancer by age 70; usually high grade, aneuploid, but ER+, PR+
Higher risk with 4486 G>T mutation
Men with BRCA2 mutation have higher risk of breast cancer also
Ovary: 15%-27% lifetime risk of adenocarcinoma in women with mutations; often younger patients with high stage tumors; BRCA mutations cause 90% of hereditary cases of ovarian carcinomas, which account for 10% of all ovarian carcinomas
Diagrams: normal and abnormal function
References: OMIM 600185, Mod Path 2005;18:1305, Hum Path 2005;36:861 (hereditary ovarian cancer)
BTK
Bruton's tyrosine kinase
Required for B cell differentiation beyond pro-B stage
Also mediates B cell receptor mediated apoptosis
Mutations cause X linked agammaglobulinemia, in which there is no B cell development
Single chain glycoprotein at 3q41-42, expressed on myeloid cells, endothelial cells, hematopoietic progenitor cells, platelets
May enhance phagocytosis upon interaction with soluble defense collagens
Note: distinguished from cC1qR (identical with the chaperone protein calreticulin) and molecular designated gC1qR (binds the globular domain of C1q)
GGT deficiencies are associated with glutathionuria, cysteine depletion
Positive staining (normal): renal tubular epithelium, pancreas, epididymis, seminal vesicles, vascular endothelium, macrophages, B cell subsets, activated T cells
Negative expression: hepatocytes
CA125
Image: Urothelial carcinoma-high grade
CAAT
Transcription related binding factor
Cadherins
See also E-cadherin, N-cadherin
Molecules that establish links between adjacent cells by forming zipper like structures at adherens junctions
Linked to cytoskeleton via catenins (cadherin to beta catenin, beta catenin to alpha catenin, alpha catenin to actin) to stabilize adherens junction
Homophilic interactions (like-like) causes clustering of embryonic cells with others from same tissue
Loss of cadherins may be first step in giving cells invasive properties
CAI
Inhibits calcium influx and calcium influx mediated pathways including arachidonic acid release and tyrosine phosphorylation
In vitro, inhibits proliferation, adhesion, motility, MMP-2 production and density independent growth of human
tumor cell lines
Has anti-angiogenic abilities
CAK
CDK activating kinase
Controls polymerase II dependent transcription
Calcium stains
With routine staining, calcium forms a blue-black lake with hematoxylin, usually with sharp edges.
von Kossa method: silver is substituted for calcium in calcium salts; light or a photographic developer turns the silver black; only stains calcium bound to an anion such as phosphate or carbonate; most useful when large amounts of phosphates and carbonates are present, as with bone
Alizarin red S forms an orange-red lake with calcium at a pH of 4.2; works best with small amounts of calcium such as in Michaelis-Gutman bodies; this method is used on Dupont ACA analyzer to measure serum calcium photometrically
Azan stain used to distinguish osteoid from mineralized bone.
Micro images: malakoplakia of bladder (von Kossa calcium stain)
Caldesmon binds calcium, calmodulin, tropomyosin and actin, and regulates smooth muscle contraction (Int J Biochem Cell Biol 1997;29:1047)
h-caldesmon is its high molecular weight isoform, found in smooth muscle cells; l-caldesmon isoform is distributed in non-muscle cells (J Biol Chem 1991;266:355)
Uses:
(1) very useful to distinguish smooth muscle cells/lesions (positive) from myofibroblastic cells/lesions (negative or only a few cells positive, AJCP 2000;114:746, Am J Dermatopathol 2006;28:105)
(2) distinguish uterine leiomyoma or leiomyosarcoma (positive) from endometrial stromal tumors (negative, AJSP 2001;25:455), but endometrial stromal tumors may have focal smooth muscle differentiation (AJSP 2002;26:1142)
(3) sensitive and specific for epithelioid peritoneal mesothelioma (positive) versus ovarian serous carcinoma (negative, AJSP 2007;31:1139) and epithelioid pleural mesothelioma (positive) versus pulmonary adenocarcinoma (negative, AJSP 2006;30:463)
Note: may be negative in epithelioid smooth muscle tumors of uterus (AJSP 2006;30:319)
Positive staining (normal): smooth muscle cells (vascular, visceral)
Positive staining (disease): angioleiomyoma (Hum Path 2007;38:645), gastrointestinal stomal tumor (61%, Pathol Oncol Res 2005;11:11), glomus tumor (Hum Path 1999;30:392), inflammatory myofibroblastic tumor (focal, AJSP 2006;30:1502), leiomyoma/leiomyomatosis (Eur J Gynaecol Oncol 2004;25:481), leiomyosarcoma (AJSP 2004;28:178 and references above, but see Appl Immunohistochem Mol Morphol 2001;9:302), myopericytoma (AJSP 2006;30:104), perivascular epithelioid cell tumors (Int J Gynecol Pathol 2005;24:341)
Negative staining (normal): endometrium, endometrial stroma, myofibroblasts (J Submicrosc Cytol Pathol 2005;37:231), pericytes
Negative staining (disease): endometrial stromal tumor (references above), fibromatosis, myofibroblastoma (Pathology 2005;37:144), myofibroblastic lesions (Int J Surg Pathol 2005;13:57), nodular fasciitis, rhabdomyosarcoma (AJSP 2005;29:1106), synovial sarcoma (AJSP 2002;26:1434)
Micro images: colon-pericrytal fibroblast sheath (fig A); leiomyosarcoma #1; #2-bladder (fig 2); lipoleiomyosarcoma (fig 4); mixed tumor of vagina-stromal cells (fig d)
Actin filament associated regulatory protein
h1 (basic) isoform is smooth muscle specific, but a late stage smooth muscle marker; described below
h2 isoform is found in smooth muscle and non muscle cells; not described below
Uses:
(1) identify myoepithelial cells in breast lesions (Histopathology 2005;47:202)
(2) help differentiate breast collagenous spherulosis (positive) from adenoid cystic carcinoma (negative, Mod Path 2006;19:1351), although adenoid cystic carcinoma is calponin positive in salivary gland tumors (Archives 1999;123:801)
Positive staining (normal): smooth muscle, myoepithelial cells (most but not all, Breast Cancer Res 2003;5:R151), myofibroblasts (AJSP 2003;27:82, Proc Natl Acad Sci USA 1993;90:999); also keratinocytes and nerve fibers (Virchows Arch 2000;437:58), choroidal non-vascular smooth muscle cells (J Anat 2005;207:381)
Positive staining (disease): atypical fibroxanthoma (30%, Virchows Arch 2002;440:404), benign fibrous histiocytoma (65%), collagenous spherulosis (Mod Path 2006;19:1351), DFSP (40%), fibromatosis (Am J Dermatopathol 2006;28:105), fibrosarcoma (60%), glomus tumor (AJSP 2002;26:301), leiomyoma, leiomyosarcoma, MFH of bone (47%, J Clin Pathol 2002;55:853), MPNST (40%), myoepithelioma-skin, myofibroblastic lesions, myofibroblasts in desmoplastic stroma of carcinomas, nodular fasciitis, solitary fibrous tumor (70%), synovial sarcoma (Histopathology 2003;42:588)
Negative staining (disease): adenoid cystic carcinoma
Micro images:
breast - adenoid cystic carcinoma (fig e) versus collagenous spherulosis (fig j); adenomyoepithelioma (fig I); myoepithelial cells #1; #2; phyllodes tumor-malignant, metastatic (fig d); sclerosing lobular hyperplasia
salivary gland - adenoid cystic carcinoma-submandibular gland; basal cell adenoma; epithelial-myoepithelial carcinoma
other - hidradenoma papilliferum; MFH of bone (fig B, F); pleomorphic adenoma of nasal cavity (fig 4b)
[Topic updated January 2008]
Calcium binding protein expressed by various cells; structurally related to S100 and inhibin
Uses:
(1) differentiate (as part of a panel) epithelioid pleural mesothelioma (positive) from lung adenocarcinoma (negative, AJSP 2003;27:1031)
(2) differentiate (as part of a panel) epithelioid peritoneal mesothelioma (positive) from ovarian serous papillary carcinoma (usually negative, AJSP 2007;31:1139)
(3) differentiate reactive mesothelial cells (positive) from carcinoma (negative) in effusion cytology (AJCP 2001;116:709, Cytopathology 2007 Oct 4 [Epub ahead of print]), ascites fluid/peritoneal lavage (Tohoku J Exp Med 2005;206:31) or pleural biopsies (AJSP 2007;31:914)
(4) differentiate (as part of a panel) mesothelioma (positive) from metastatic renal cell carcinoma (negative, Histopathology 2002;41:301)
(5) differentiate (as part of a panel) ovarian Sertoli-Leydig tumors (positive) from sertoliform endometroid carcinoma (negative, Archives 2007;131:979)
(5) differentiate schwannoma (strong staining) from neurofibroma (negative or weak/focal staining, AJCP 2004;122:552)
(6) identify peritoneal invasive implants of serous borderline tumors of the ovary by lack of calretinin+ mesothelial cells (Mod Path 2006;19:364)
(7) marker for normally functional endometrial stromal cells (Pathol Res Pract 2007;203:79)
Interpretation: nuclear and cytoplasmic staining
Positive staining (normal): adipocytes (Hum Path 2006;37:312), endometrial stromal cells, Leydig cells of testis, mast cells, mesothelial cells, neurons of brain, ovarian theca-lutein and theca interna cells, Sertoli cells (Hum Path 2003;34:994)
Positive staining (disease): mesothelial hyperplasia and cysts, mesothelioma (strong diffuse staining in almost all epithelioid and lymphohistiocytic subtypes, 57% of sarcomatoid subtypes, AJSP 2007;31:711, Mod Path 2007;20:248); also ameloblastoma (stellate reticulum-like epithelium, Histopathology 2000;37:27), adenomatoid tumors (AJSP 2003;27:969), adrenal cortical tumors (96%, Mod Path 2003;16:591), cardiac myxoma (AJCP 2000;114:754), cervical mesonephric adenocarcinoma (88%, AJSP 2001;25:379), colorectal adenocarcinoma (various by tumor differentiation, AJSP 1999;23:701), desmoplastic small round cell tumors (20%, Mod Path 2003;16:229), FATWO (Hum Path 1999;30:856), granular cell tumor (AJCP 2003;119:259), lipoma and liposarcoma (Hum Path 2006;37:312), lung carcinoma (adenocarcinoma-11%, giant cell carcinoma-67%, large cell-38%, small cell-49%, AJSP 2003;27:150), schwannoma (AJCP 2004;122:552), sex cord stromal tumors (50-100%, including inhibin negative tumors, AJSP 2005;29:143, AJSP 2002;26:1477); synovial sarcoma (most, AJSP 2001;25:610), thymic carcinoma and thymoma (some, Hum Path 2003;34:1155)
Calretinin (continued)
Negative staining: adrenal medullary tumors including pheochromocytoma, mucinous cysts, renal cell carcinoma (usually, Histopathology 2002;41:301)
Micro images:
mesothelium - hyperplastic mesothelium and submesothelial stromal cells are calretinin+
mesothelioma - clear cell variant (pleura); deciduoid variant #1 (fig 6); #2 (fig d); epithelioid variant #1; #2 (fig c); #3 (fig d) and lung squamous cell carcinoma (fig e); various images
other - adrenal gland adenomatoid tumor (fig C); adrenal gland corticomedullary mixed tumor (fig C/D); adrenal gland pheochromocytoma is negative, but ganglioneuromatous foci is positive (fig B); adrenocortical carcinoma (fig B); cardiac myxoma (fig C); invasive implants show loss of calretinin+ mesothelial cells; neurons in colon wall; noninvasive implants are surrounded by calretinin+ mesothelial cells; ovarian fibroma; ovarian granulosa cell tumor #1 (adult); #2; primary retroperitoneal mucinous cystadenoma (fig 7)
CAM 5.2
can
Gene at 9q34
Translocated in some AML cases
CAP 4
Protein associates CD95 (Fas) death inducing signaling complex (DISC) in a ligand dependent manner
Caspases
Cysteine proteases that act as apoptotic cell death effectors by cleaving polypeptides on the carboxyl end of aspartate residues
Synthesized as inactive proenzymes, may be activated by other caspases (initiator caspases), which cause a cascade of activation similar to coagulation or complement, and eventually cleave the nuclear enzyme PARP and ICAD
Cleavage of ICAD allows the release of CAD, which relocalizes from the cytoplasm into the nucleus, where it cleaves genomic DNA
Caspase 3
Cleaves PARP and ICAD
Caspase 7
Involved in execution stage of apoptosis
Caspase 8
Initiator caspase, also cleaves Bid, a bcl2 homolog that activates caspase 9 by releasing cytochrome C from mitochondria
Positive staining (disease): pancreatic adenocarcinoma, breast carcinoma
Caspase 9
Initiates activation of caspase 3, 6 and 7
Cathepsins
A group of lysosomal proteinases or endopeptidases found in aqueous extracts of a variety of animal tissue
Function optimally within an acidic pH range
Cathepsin B
Lysosomal cysteine protease related to tumor invasiveness
Inhibited by cystatin C (an endogenous cysteine protease inhibitor)
Usually acts only in cell cytoplasm, but in malignant tumors, is secreted extracellularly and degrades extracellular matrix so tumor cells can invade
Associated with focal adhesions
Highest staining at invasive edge of tumor
Associated with invasive properties of tumors; may degrade basement membrane
High expression associated with poor disease free survival in gliomas (Hum Path 2005;36:1008)
Brain: inhibitors prevent infiltration of glioblastoma cells into normal brain in vivo
Colon: predicts poor prognosis in colonic carcinoma
CCR5
Also called CD195
Macrophage surface receptor and attachment site for HIV and SIV, with CXCR4 (CD184); works with CD4
Receptor for CD8 chemokines RANTES, MIP 1-alpha and MIP 1-beta.
CDC2 / CDK1
Also called Cyclin Dependent Kinase 1
Member of cyclin dependent kinase family, which regulates phase transitions and checkpoints within the cell cycle
Nuclear protein that is subunit of M phase promoting factor, together with cyclin B subunit
Not expressed in normal esophagus; rare to occasional expression in Barrett’s esophagus with low grade dysplasia, increasing to diffuse expression in 95% with high grade dysplasia; expression correlates with progression of esophageal adenocarcinoma in cell lines (AJSP 2005;29:390)
EM-1521, a CDC2/CDK1 inhibitor, is theoretical antitumor therapy for esophageal adenocarcinoma
Low levels associated with reduced survival in mantle cell lymphoma (Mod Path 2005;18:1223)
Interpretation: staining in mantle cell lymphoma is predominantly cytoplasmic and partial nuclear
Positive staining (normal): germinal center (but not mantle zone) of benign lymph nodes
Micro images: staining in tonsil (fig 2b), mantle cell lymphoma (2e/2f)
CDH1
Gene encodes E-cadherin protein
Inactivating mutations may be a risk factor for diffuse gastric carcinoma
CDKs
Cyclin dependent kinases
Cell cycle progression is regulated by complexes formed between cyclins and CDKs
CDK4
Gene is at 12q13-15
Binds to D type cyclins in G1 phase of cell cycle, controls G1-S transition via phosphorylation of retinoblastoma gene; inhibited by p16INK4a
Amplified in well differentiated liposarcoma and dedifferentiated liposarcoma (amplification detected by comparative genomic hybridization, qualitative PCR, FISH; also immunostain which correlates with gene amplification
Uses: distinguish well differentiated liposarcoma (positive) from benign adipose tumors (negative) and dedifferentiated liposarcoma (positive) from poorly differentiated sarcomas (negative); CDK4 is more specific but less sensitive than MDM2 (AJSP 2005;29:1340)
CDK6
Binds to D type cyclins in G1 phase of cell cycle, controls G1-S transition via phosphorylation of retinoblastoma gene; inhibited by p16INK4a
CDX2
Homeobox gene that encodes a nuclear transcription factor critical for intestinal embryonic development, and specific for intestinal epithelium
Homologue of Drosophila melanogaster homeobox gene - caudal
Also has influence in anteroposterior patterning
May be a tumor suppressor; regulates expression of p21 and COX2
Uses: distinguish (1) primary and secondary colorectal adenocarcinomas (Archives 2005;129:920), (2) primary bladder adenocarcinoma vs. colorectal carcinoma extending/metastatic to bladder - negative CDX2 and negative villin suggests bladder primary (Mod Path 2005;18:1217)
Positive staining (normal): nuclei of intestinal epithelium lining colonic villi and crypts, subset of pancreatic epithelial cell, gastric, esophageal and bladder intestinal metaplasia
Positive staining (disease): intestinal adenocarcinomas (86-100% of colorectal cancers, less if poorly differentiated), gastric adenocarcinoma (60-70%, with variable intensity), urinary bladder adenocarcinomas (47-100%), mucinous adenocarcinomas of ovary and lung; also gastric adenocarcinoma, rarely other carcinomas
Negative staining: bladder urothelium, urothelial carcinoma, breast carcinoma
Micro images: (1) colorectal carcinomas; colorectal carcinoma staining; staining in pancreatic and endometrial tumors; (2) various images #1; #2; (4) CDX2 staining in A: metastatic colonic carcinoma to lung; B: pancreatic ductal adenocarcinoma in duodenum; C: ampullary adenocarcinoma; (5) poorly differentiated gastric carcinoma - fig 4a: CK20; 4b: MUC5AC; 4c: MUC6; 4d: DAS-1; 4e: CDX2; bladder adenocarcinoma - (a) secondary colorectal is CDX2+ vs. (b) primary bladder is weak/negative
References: Archives 2005;129:1100, Mod Path 2005;18:1217 (bladder primary vs. secondary colorectal)
CEA
See CD66e in CD Markers CD50-99 chapter
CED-3
Required for apoptosis in C. elegans
Negatively regulated by CED-9 (bcl2)
Analogous to caspases (ICE and family) in mammals
CED-4
Required for apoptosis in C. elegans; no known mammalian counterpart
Negatively regulated by CED-9 (bcl2) and bcl-xL
Overexpression causes apoptosis in cells which normally survive
Loss of function mutations prevent normal cell death
Biochemically links bcl2 and ICE/FLICE
CED-9
bcl2 homolog in C. elegans
CENP-F
Also known as mitosin
Member of CENP centromere protein family, involved in formation of centromere and organization of kinetochore during mitosis
Interpretation: staining in mantle cell lymphoma is nuclear
Micro images: staining in tonsil (fig 2c), mantle cell lymphoma (2g)
Ceramide
Members of the class of neutral glycosphingolipids
Basic units of sphingolipids
Are sphingoids attached via their amino groups to a long chain fatty acyl group
Fabry’s disease: abnormally accumulate
Chaperones
Proteins which help other proteins fold correctly by transient binding to interactive surfaces (hydrophobic areas), which otherwise might aggregate
Name is accurate since it has no actual positive effect but prevents negative effects
Important after environmental stress which causes proteins to unfold
As a translated protein grows, it becomes increasingly available to chaperones; the protein is released into the intracellular space only when it is folded enough to prevent aggregation
CHEK2
Gene encodes cell-cycle checkpoint kinase implicated in DNA repair processes involving BRCA1 and p53
Mutation CHEK2*1100delC, which lacks kinase activity, seen in 5.1% of breast cancer patients without BRCA1 or BRCA2 mutations vs. 1.1% of healthy individuals
Mutation CHEK2*1100delC confers estimated 2 x risk of breast cancer in women without BRCA1 or BRCA2 mutations; no increased risk in patients with BRCA1 or BRCA2 mutations, Nat Genet 2002;31:55
Chloroacetate esterase
Also called specific esterase, naphthol AS-D chloroacetate esterase
Useful for demonstrating myeloid differentiation, although negative in 25% of cases, particularly with immature granulocytic and monocytic neoplasms (Archives 2005;129:32)
Enzyme cytochemistry-positive: AML-M1, M2, microgranular M3; granulocytic sarcomas, neutrophils
Enzyme cytochemistry-negative: ALL
CHOP
12q13
Also called GADD153, DDIT3
Transcription factor translocated via t(12;16)(q13;p11) in 90% of myxoid or round cell liposarcomas
Chromaffin
Chromaffin cells have cytoplasmic granules that appear brown when fixed with a dichromate solution
Traditionally associated with adrenal medulla or extraadrenal paraganglion tissues (pheochromocytomas)
Types of stains for chromaffin include: Modified Giemsa, Schmorl's, Wiesel's
Chromogranin
Specific but not sensitive immunostain for neuroendocrine cells
Acidic glycoproteins in the soluble fraction of neurosecretory granules
Positive more often for well differentiated vs. poorly differentiated tumors
Granular cytoplasmic pattern in small cell carcinoma reflects neurosecretory granules
Micro images: neuroendocrine carcinoma of ampulla: H&E, chromogranin; gallbladder paraganglioma (fig 2a); colloid carcinoma of breast - ER+, PR+, chromogranin+, synaptophysin+; metastatic small intestinal carcinoid to breast
Micro images: neuroendocrine carcinoma of breast #1; #2
CK
See cytokeratin
c-kit
See CD117 (CD Markers outline)
Claudins
Multigene family of integral membrane proteins active in tight junction formation and function
At least 24 known members, expressed in tissue specific pattern; usually cells from a specific organ express multiple claudin proteins
Variation in expression associated with malignant tumors
Positive staining (normal): epithelial and endothelial cells
Claudin-1
Tight junction-associated protein
May have reduced expression in invasive vs. benign breast lesions
Positive staining (tumor): 30-50% of soft tissue and intramucosal intestinal perineuriomas (AJSP 2005;29:859, AJSP 2005;29:845). gastric intestinal type adenocarcinoma (less frequently in diffuse type, Hum Path 2005;36:886)
Claudin-4
May be related to breast epithelial differentiation
Clusterin
Glycoprotein implicated in apoptosis and other cellular functions
Strongly expressed in follicular dendritic cell tumors, weak/no expression in other dendritic cell tumors
Among spindle cell neoplasms, has high sensitivity and specificity for follicular dendritic cell tumors (Mod Path 2005;18:260)
Positive stains (disease): anaplastic large cell lymphoma (80-100% of systemic cases, 40-60% of primary cutaneous cases), diffuse large B cell lymphoma (12%), carcinomas of breast, colon, pancreas, prostate
Micro images: follicular dendritic cell tumor: H&E and clusterin (b/e)
c-MET
Gene at 7q31-34; receptor for hepatocyte growth factor receptor
A tyrosine kinase that mediates cell motility, proliferation, invasiveness, angiogenesis and morphogenetic differentiation
Activating mutations are present in papillary renal cell carcinoma; missense mutation in 6% of thyroid carcinoma (papillary, follicular and medullary, AJSP 2005;29:544); high levels of MET mRNA and protein expressed in papillary thyroid carcinoma
Positive staining (disease): melanoma, melanocytic lesions
c-myc
Proto-oncogene at 8q24.1 produces short lived nuclear phosphoprotein
Overexpressed by t(8;14)(q24;q32.3), t(8;22);(q24;11) and t(2;8);(p11-12;q24), which translocate c-myc gene next to immunoglobulin genes in Burkitt’s lymphoma
Gene expressed in virtually all eukaryotic cells; expression usually tightly controlled
Immediate early growth response gene; rapidly induced when quiescent cells receive a signal to divide; required for cells to enter S phase
By itself, binds DNA poorly; forms stable sequence specific DNA binding heterodimers with max; myc-max recognizes E-box sequence CACGTG and activates transcription of nearby growth promoting genes
Has leucine zipper motif: leucine residues that project from every other turn of the alpha helix (every 7th amino acid is leucine), which interdigitates with another leucine zipper
In humans, deletion causes embryonic death
t(8;14) also frequent in AIDS-related lymphomas, diffuse large-cell lymphomas, posttransplant lymphoproliferative disease, B-ALL (leukemic counterpart of Burkitt's lymphoma)
t(8;14)(q24;q11) present in 10-15% T-ALL
Breast cancer: amplified in 20-30% of cases; associated with HER2 amplification and poor outcome (Hum Path 2005;36:634)
Burkitt’s lymphoma: 90% have translocation of c-myc or variants; translocation causes continuous stimulation by adjacent enhancer element of immunoglobulin gene or mutations in myc gene regulatory sequences, that leads to increased constitutive levels; continuous growth stimulation may lead to polyclonal pre-B proliferations, then clonal proliferations, usually ALL-L3
Lung-small cell carcinoma: amplified
Neuroblastoma: amplified
CNA.42
Follicular dendritic cell marker
More sensitive but less specific than CD21 or CD35
Positive staining (normal): mononuclear cells, follicular dendritic cells
Positive staining (disease): Reed-Sternberg cells, some sarcomas
Collagen
Type I collagen: dermis, tendons and bone
Type II collagen: cartilage
Type III collagen: fetal skin, scars, arterial walls
Type IV collagen: normal constituent of basement membrane surrounding noninvasive glandular epithelium
There is discontinuous or complete absence of basement membrane staining surrounding colonic adenocarcinoma, AJSP 2002;26:206
Uses: double immunostaining of type IV collagen with cytokeratin is useful to detect microinvasion in VIN or CIN (Archives 2005;129:747)
Micro images: double immunostaining with cytokeratin #1; #2
Collagen stains
See Trichrome
Collagen - type II
Specific marker of normal and neoplastic chondrocytes
Specific and sensitive for mesenchymal chondrosarcomas vs. other small cell sarcomas except chondroblastic small cell osteosarcomas (Mod Path 2005;18:1088)
Micro images: mesenchymal chondrosarcoma - a1-c1: H&E; a2-c2: vimentin; a3-c3: S100; a4-c4: collagen type II
Complexity
A possible theory of attack for tumor cells
Normal cells have redundant pathways to transmit information from outside the cell to the cytoplasm or nucleus
Normal cells also have cross talk between signaling systems, and can modulate parallel pathways to respond to chemical challenges
Cancer cells may become dependent on specific signal transduction pathways for survival, making them more sensitive to agents that target a key regulatory signal pathway, while normal cells are unaffected
Congo red
Also called amyloid stain
Must examine stained tissue with standard and polarized light
Amyloid under polarized light has apple green birefringence, based on the molecule being in an antiparallel beta-pleated sheet.
Note: non-amyloid related green birefringence can occur due to excess dye retained by the tissue
Micro images: medullary carcinoma of thyroid gland-staining lower right; amyloid in adrenal gland; primary localized laryngeal amyloidosis (polarized light-fig F); amyloid tumor of breast - fig 1: coarse calcifications of right breast; 2: H&E; 3: Congo red staining; 4: Congo red under polarized light; cardiac amyloidosis under polarized light
Connexin 43
Also called Cx43
Allows direct gap junctional intercellular communication
Associated with growth control and neoplasia suppression
Up regulated by retinoic acid
Positive staining (normal): diffuse suprabasal staining of upper aerodigestic tract squamous mucosa (apparent marker of squamous cell differentiation)
Expression progressively decreases in dysplasia to well differentiated to poorly differentiated squamous cell carcinomas
COX2
See cyclooxygenase 2 (below)
CPP-32
Proenzyme activated by ICE and granzyme B (a cytotoxic T cell granule serine protease)
Activation is controlled by physical isolation of protease
Autocatalysis appears to play an important role in pro-enzyme activation
Member of ICE family
Cleaves and inactivates PARP
Activation is specifically required for apoptosis; CPP-32 inhibition prevents apoptosis in vivo/vitro
CREB
Cyclic adenosine monophosphate Response Element Binding protein
A transcription factor
Binds with serum response element proteins to mediate growth factor induction of c-fos by binding to c-fos promoter
CSK
Tyrosine kinase that negatively regulates LYN and SYK kinases
CTLA-4
Also called CD152
Negative regulator of T cell activation
CTLA4 restriction fragment length polymorphisms are linked to various autoimmune disorders
Shares sequence homology with CD28; also shares ligands CD80 and CD86 with CD28
Positive staining (normal): activated but not resting T cells, activated B cells
References: (123890)
CXCR2
Also called Interleukin 8 receptor, beta subunit, CDw128b
Chemokine receptor, powerful neutrophil chemotactic factor, particularly to sites of inflammation
Binds multiple CXC chemokines including IL-8
Positive staining (normal): mature granulocytes, projection neurons, neuroendocrine cells (various)
Positive staining (disease): carcinoids, atypical carcinoids, metastatic carcinoids, pituitary adenomas, pheochromocytomas, medullary carcinomas
Negative staining: small cell carcinoma of lung/cervix, large cell lung neuroendocrine carcinoma, Merkel cell carcinoma, neuroblastoma, melanoma
Also called CD183
Receptor for some chemokines; binding of chemokines to CD183 induces integrin activation, cytoskeletal changes and chemotactic migration in inflammation-associated effector T cells
CD183+ T cells detected in inflamed tissues of patients afflicted with juvenile rheumatoid arthritis, multiple sclerosis, sarcoidosis, hepatitis C
Positive staining (normal): T cells in inflamed tissue, eosinophils, plasmacytoid dendritic cells, hematopoietic progenitors
Negative staining: naïve T cells in peripheral blood
Cyclins
Regulatory subunits of cyclin dependent kinases (CDKs)
Control the passage of proliferating cells through key checkpoints in the cell cycle (G1 to S, G2 to M) through overexpression of positive growth regulators such as cyclin dependent kinases (CDKs) and underexpression of inhibitory growth regulators, such as CDK inhibitors
Cyclin A
Gene is site of integration of part of the hepatitis B virus in hepatocellular carcinoma
Acts from late G1 phase through M phase of cell cycle
Forms complex with CDK2 during late G1-S phase, and with CDC2 during G2-M phase
Cyclin B1
G2-M phase regulator
Cyclin D1
Also called bcl1 - “b cell lymphoma #1”
Coded by BCL1 / PRAD1 (parathyroid adenoma 1) gene on #11q13
Responsible for transition to S phase by phosphorylating the retinoblastoma gene product, which releases transcription factors to initiate DNA replication
Overexpression promotes transformation to a malignant phenotype; overexpressed in many tumors
Interpretation: nuclear stain
Uses:
(a) Mantle cell lymphoma: characterized by a t(11;14) translocation, which places the cyclin D1 gene next to an immunoglobulin heavy chain enhancer gene; among lymphomas, cyclin D1 expression is very specific for mantle cell lymphoma
(b) Parathyroid: overexpressed in 18% of parathyroid adenomas, strong staining in carcinomas
Positive staining (nuclear stain): mantle cell lymphoma; various carcinomas, multiple myeloma (40%), hairy cell leukemia (25%), B-CLL (13%, AJSP 2004;28:801), some parathyroid adenomas and parathyroid carcinomas
Micro images: mantle cell lymphoma
Virtual slides: mantle cell lymphoma
Cyclin D2
Cell cycle regulatory protein that facilitates G1 to S phase transition
Expression associated with poorer prognosis in diffuse large B cell lymphoma (Mod Path 2005;18:1377)
Positive staining (disease): diffuse large B cell lymphoma (14%)
Cyclin D3
Nuclear stain
Expression correlates with expression of phosphorylated (activated) STAT3 (Hum Path 2005;36:806)
Micro images: expression in ALK+ and ALK- anaplastic large cell lymphomas
Cyclin E
A 50-kDa protein that complexes with cdk2 in the late G1 phase of the cell cycle
Interpretation: nuclear staining
Cyclooxygenase 2 (COX2)
Cyclooxygenases 1 (COX1) and 2 (COX2), also known as prostaglandin H synthase, catalyze formation of prostaglandin from arachidonic acid
COX1 is constitutive form of enzyme on 9q; COX2 is inducible isoform on 1q, has 61% sequence homology with COX1
Regulated by mitogens, tumor promoters, cytokines, serum, free fatty acids, NSAIDs, selective COX2 inhibitors
Increased expression associated with poor clinical outcome in stage I/II non-small cell lung carcinoma (Archives 2005;129:1113), possibly poorer outcome in follicular thyroid carcinoma (Archives 2005;129:736)
Interpretation: cytoplasmic staining
Positive staining (normal): endothelial cells
Positive staining (disease): breast, colorectal, esophageal, liver, lung, ovary, pancreas, prostate, skin, stomach tumors
Micro images: lung adenocarcinoma (A: COX2+; B: COX2-; C: endothelial cells are positive control); fig 7-staining in follicular carcinoma; arachidonic acid pathway
Cyld1
Tumor suppressor gene at 16p involved in familial cylindromatosis and sporadic cylindromas
Cystatin C
Strongest inhibitor of cathepsin B
Low expression associated with poor disease free survival in gliomas (Hum Path 2005;36:1008)
Definition: family of water-insoluble intracytoplasmic structural proteins that are the dominant intermediate filament proteins of epithelial and hair forming cells; also present in epithelial tumors
Within a cell, form a dense network radiating from the nucleus to the plasma membrane
Act as cytoplasmic scaffold that gives epithelial cells the ability to sustain mechanical and non-mechanical stress
Keratin intermediate filaments are highly dynamic structures and are reorganized during mitosis and apoptosis; reorganization is mediated by posttranslational phosphorylation, glycosylation, transglutamination and proteolysis, or through interaction with 14-3-3 or other proteins
Expression depends on cell type and differentiation status
Over 25 subtypes are defined based on molecular weight (40 to 68 kDa) and isoelectric pH (5 to 8)
Moll catalog number (Cell 1982;31:11) ranges from 1 (highest molecular weight) to 23 (lowest molecular weight)
New nomenclature exists (J Cell Biol 2006;174:169)
Divided into Type I (acidic; CK10, CK12-19, 40-56.5 kDa) and Type II (neutral-basic, CK1-CK8, 53-67 kDa)
Type I genes are expressed at 17q21.2, type II genes at 12q13.13
Proteins are obligate heteropolymers with equimolar amounts of type I and type II proteins that form functional filaments, such as CK8/18, CK5/14, CK1/10
Also divided into low molecular weight (CAM 5.2, 34 beta E11) and high molecular weight (34 beta E12); pankeratin cocktails contain AE1 and AE3 and possibly also CAM 5.2
Genes are KRT1 for keratin 1, KRT2 for keratin 2, etc.
Uses:
(1) diagnose epithelial (cytokeratin+) versus nonepithelial cells / tumors (usually cytokeratin negative but there are many exceptions)
(2) diagnose particular types of epithelial tumors based on staining patterns of particular cytokeratins - dot like staining is suggestive of neuroendocrine tumors
(3) in rebiopsies of tumors, don’t assume that all keratin+ cells are residual tumor cells (AJSP 2007;31:390)
Negative staining (usually): endothelium, mesenchymal cells
Micro images: cytokeratin network of cell #1; #2 (CK8, 18, 19)
Highest molecular weight keratin (67-68 kDa)
Produced by KRT1 gene in complex manner (PLoS Genet 2006;2:e93)
Associates with CK10
Keratin 1b is expressed in eccrine sweat glands (J Invest Dermatol 2005;125:428)
Reduced expression in HPV infection (Cancer Res 1990;50:3709)
Mutations are associated with epidermolytic hyperkeratosis / bullous congenital ichthyosiform erythroderma (Dermatol Online J 2006;12:6), Greither’s syndrome (J Am Acad Dermatol 2005;53:S225), striate palmoplantar keratoderma (J Invest Dermatol 2002;118:838)
Uses: no significant clinical use by pathologists
Positive staining (normal): endothelial cells, skin and other squamous epithelium (suprabasal spinous and granular layers), thymic Hassal’s corpuscle
Positive staining (disease): angiosarcoma (73%), epithelioid hemangioendothelioma (100%), epithelioid sarcoma (70%), hemangioma (often), schwannoma (62%), squamous cell carcinomas-keratinizing, synovial sarcoma (28%), vascular tumors (greater in well versus poorly differentiated tumors)
Micro images: eccrine sweat gland expression
References: Hum Path 2001;32:873, OMIM 139350
Molecular weight (CK2e) is 65.5-65.8 kDa
Associates with CK10 (UniProtKB)
Mutations cause ichthyosis bullosa of Siemens (Br J Dermatol 2005;152:1353)
K2e (epidermis) and K2p (palate) are encoded by separate genes, with < 75% identity at primary structural level; thus, are not true isoforms, although they cannot be distinguished by conventional 2D electrophoresis (HopkinsMedicine)
Uses: no significant clinical use by pathologists
Positive staining (normal): skin (upper spinous and granular cells, Br J Dermatol 1999;140:582)
References: OMIM 600194, Exp Cell Res 1992;202:132
Molecular weight is 64-65 kDa
Associates with CK12
Mutations in KRT3 gene may cause Meesmann corneal dystrophy (Cornea 2005;24:928)
Uses: no significant clinical use by pathologists
Positive staining (normal): corneal epithelium (full thickness), limbus epithelium (suprabasal)
Negative staining: conjunctival epithelium
Micro images: suprabasal staining of limbus epithelium cultured using air-lifting (AL) technique (fig A/B)
References: OMIM 148043
Molecular weight is 59 kDa
Associates with CK13
Downregulated in head and neck squamous cell carcinoma (Acta Otolaryngol 2006;126:967)
Uses: no significant clinical use by pathologists
Case reports: mutation in KRT4 gene causes white sponge nevus (Br J Dermatol 2003;148:1125)
Positive staining (normal): suprabasal cells of nonkeratinized stratified squamous epithelium of esophagus and cornea; also anus, larynx, pharynx, tongue (J Biol Chem 1998;273:23912)
Micro images: epidermis before and after treatment with retinoic acid
References: OMIM 123940
Molecular weight is 58 kDa
Major partner is CK14, but related to cytokeratin 6 (antibodies are often to CK5/6)
Common antibody is 34BE12
Mutations may cause epidermolysis bullosa simplex (Hum Mutat 2006;27:719), Dowling-Degos disease (Am J Hum Genet 2006;78:510)
Important in tooth enamel formation (J Biol Chem 2003;278:20293)
Interpretation: diffuse cytoplasmic staining with perinuclear enhancement (AJSP 2001;25:43)
Uses:
(1) helps defines a basal-like subtype of invasive ductal carcinoma of the breast that is usually CK5/6+, ER-, PR-, HER2-, EGFR+ with poorer prognosis (Clin Cancer Res 2006;12:1533); associated with premenopausal African American women (JAMA 2006;295:2492), BRCA1 (J Natl Cancer Inst 2003;95:1482, Mod Path 2005;18:1321) and brain metastases (AJSP 2006;30:1097