DOG-1 is a calcium-activated chloride channel protein (a.k.a. anoctamin-1 or TMEM16a), and has been found to be ubiquitously expressed in GI stromal tumors irrespective of KIT or PDGFRA mutation status.  This antibody appears to stain a significant subset of CD117 (c-kit) negative cases (36-46%).  Approximately 50% of DOG-1 negative GISTs will express CD117.  In the setting of a GIST differential diagnosis, DOG-1 appears to have specificity comparable to CD117.  There appears to be expression on a small subset of synovial sarcomas.  Normal staining by DOG-1 can be found in interstitial cells of Cajal.  Membraneous and apical staining / reactivity may be seen with DOG-1 in non-GIST tumors / cells.

 

In addition to normal expression in interstitial cells of Cajal in the GI tract, luminal expression can be seen in the gastric mucosa, pancreatic centroacinar cells, intrahepatic bile duct epithelium, bladder, and gallbladder epithelium.  Acinic cells in the salivary gland express DOG-1 (cytoplasmic), and may be helpful in confirming the diagnosis of an acinic cell carcinoma.

 

Clone:  K9 (no joke)

Titer: 1:400

Hadi Yaziji, AIMM Annual Meeting, “New Antibodies in Diagnostic Immunohistochemistry”, presentation, 2010.

 

West RB, et al. American Journal of Pathology.  Vol. 165, No. 1, July, 2004.

 

Chan, J. K. C. (2013). Newly Available Antibodies With Practical Applications in Surgical Pathology. International Journal of Surgical Pathology, 21(6), 553–572. doi:10.1177/1066896913507601 

 

Liegl-Atzwanger, B., Fletcher, J. A., & Fletcher, C. D. M. (2010). Gastrointestinal stromal tumors. Virchows Archiv : an International Journal of Pathology. doi:10.1007/s00428-010-0891-y

 

Patil, D. T., & Rubin, B. P. (2011). Gastrointestinal stromal tumor: advances in diagnosis and management. Archives of Pathology & Laboratory Medicine, 135(10), 1298–1310. doi:10.5858/arpa.2011-0022-RA

 

Chan JKC. Newly Available Antibodies With Practical Applications in Surgical Pathology. International Journal of Surgical Pathology. 2013;21: 553–572. doi:10.1177/1066896913507601 

D2-40 is a marker for a sialoglycoprotein found on lymphatic endothelium.  This marker is most commonly used to identify lymphatic invasion, and can help differentiate between lymphatic or vascular invasion with the additional support of a general endothelial marker (e.g. CD31 or CD34), which mark both vascular and lymphatics.  It is not recommended to use D2-40 without CD31 and/or CD34 when evaluating for lymphatic invasion.  Other cell types (including myoepithelial cells in the breast) can also express D2-40, which may result in misidentification of lymphatic invasion.

 

In addition expression is also found in germ cell neoplasia and fetal testicular monocytes.  (Mohammad and Ellis)

 

D2-40 will also be positive in mesotheliomas, but negative in adenocarcinomas.  Chu et al. showed 96% of epithelioid mesotheliomas and 65% of ovarian serous carcinomas reacted with D2-40 with membraneous staining.  Other carcinomas generally did not express D2-40 in their study.  There is no evidence that D2-40 is helpful with spindle-cell/sarcomatoid mesotheliomas.

D2-40 is expressed in approximately 2/3rds of cases of Kaposi’s Sarcoma.  It stains in a similar pattern as CD31 and CD34.

Seminomas show expression for D2-40, along with a subset of embryonic carcinomas.  Yolk sac tumors are not know to express D2-40. (Bai, et al.)

Bai S, Wei S, Pasha TL, Yao Y, Tomaszewski JE, Bing Z. Immunohistochemical Studies of Metastatic Germ-Cell Tumors in Retroperitoneal Dissection Specimens: A Sensitive and Specific Panel. International Journal of Surgical Pathology. 2013;21: 342–351. doi:10.1177/1066896912471849

 

Rosado FGN, Itani DM, Coffin CM, Cates JM. Utility of immunohistochemical staining with FLI1, D2-40, CD31, and CD34 in the diagnosis of acquired immunodeficiency syndrome-related and non-acquired immunodeficiency syndrome-related Kaposi sarcoma. Arch Pathol Lab Med. 2012;136: 301–304. doi:10.5858/arpa.2011-0213-OA

 

Ordóñez NG. Immunohistochemical diagnosis of epithelioid mesothelioma: an update. Arch Pathol Lab Med. 2005;129: 1407–1414.

 

Wick MR. Immunohistochemical approaches to the diagnosis of undifferentiated malignant tumors. Annals of Diagnostic Pathology. 2008;12: 72–84. doi:10.1016/j.anndiagpath.2007.10.003

 

Marchevsky AM. Application of immunohistochemistry to the diagnosis of malignant mesothelioma. Arch Pathol Lab Med. 2008;132: 397–401.

 

Mohammed RAA, Martin SG, Gill MS, Green AR, Paish EC, Ellis IO. Improved methods of detection of lymphovascular invasion demonstrate that it is the predominant method of vascular invasion in breast cancer and has important clinical consequences. Am J Surg Pathol. 2007;31: 1825–1833. doi:10.1097/PAS.0b013e31806841f6

Desmin is a muscle marker for intermediate filaments, which are present in smooth and striated muscle.  It shows variable myofibroblastic expression.  It is most commonly used to identify muscle differentiation in neoplastic processes (e.g. leiomyoma, rhabdomyosarcoma, etc.).

 

It is interesting that reactive mesothelial cells are often positive for desmin (>50%), compared to mesothelioma (<10%) or carcinoma (<5%).

 

Davidson, B., Nielsen, S., Christensen, J., Asschenfeldt, P., Berner, A., Risberg, B., Johansen, P.  (2001).  The role of desmin and N-cadherin in effusion cytology: a comparative study using established markers of mesothelial and epithelial cells.  American Journal of Surgical Pathology, Nov;25(11):1405-12.

 

Minato, H., Kurose, N., Fukushima, M., Nojima, T., Usuda, K., Sagawa, M., et al. (2014). Comparative Immunohistochemical Analysis of IMP3, GLUT1, EMA, CD146, and Desmin for Distinguishing Malignant Mesothelioma From Reactive Mesothelial Cells. American Journal of Clinical Pathology, 141(1), 85–93. doi:10.1309/AJCP5KNL7QTELLYI 

CK20 is an intermediate filament with a selective expression pattern in different carcinomas, which when combined with CD7 is useful in the work up of carcinomas of unknown primary origin.

 

Common expression patterns in carcinoma (Dennis, JL, et al).

 

Moll, RT, et al.  Cytokeratin expression in various tumors.

Key:  “+/-“, focal staining in some cases. “=“, negative, “+”, positive.

Hadi, AIMM Annual Meeting, “The Thirty Most Important Antibodies”, presentation, 2011.

 

Dennis, J. L., Hvidsten, T. R., Wit, E. C., Komorowski, J., Bell, A. K., Downie, I., et al. (2005). Markers of adenocarcinoma characteristic of the site of origin: development of a diagnostic algorithm. Clinical Cancer Research : an Official Journal of the American Association for Cancer Research, 11(10), 3766–3772. doi:10.1158/1078-0432.CCR-04-2236  

 

Moll, R., Divo, M., & Langbein, L. (2008). The human keratins: biology and pathology. Histochemistry and Cell Biology, 129(6), 705–733. doi:10.1007/s00418-008-0435-6

CK7 is an intermediate filament with a selective expression pattern in different carcinomas, which when combined with CD20 is useful in the work up of carcinomas of unknown primary origin.

 

Common expression patterns in carcinoma (Dennis, JL, et al).

 

Moll, RT, et al.  Cytokeratin expression in various tumors.

Key:  “+/-“, focal staining in some cases. “=“, negative, “+”, positive.

Hadi, AIMM Annual Meeting, “The Thirty Most Important Antibodies”, presentation, 2011.

 

Dennis, J. L., Hvidsten, T. R., Wit, E. C., Komorowski, J., Bell, A. K., Downie, I., et al. (2005). Markers of adenocarcinoma characteristic of the site of origin: development of a diagnostic algorithm. Clinical Cancer Research : an Official Journal of the American Association for Cancer Research, 11(10), 3766–3772. doi:10.1158/1078-0432.CCR-04-2236  

 

Moll, R., Divo, M., & Langbein, L. (2008). The human keratins: biology and pathology. Histochemistry and Cell Biology, 129(6), 705–733. doi:10.1007/s00418-008-0435-6  

CK5 is a high molecular weight cytokeratin that stains stratified squamous epithelium (e.g. skin, tongue mucosa, etc.), basal cells of the prostate gland, myoepithelial cells in breast tissue, and mesothelial cells/mesothelioma.  Therefore CK5 is an excellent marker, which can be used in a variety of diagnostic applications.

 

CK5 is useful in the diagnosis of squamous cell carcinoma, urothelial carcinoma, mesothelioma, thymic tumors, and skin appendage tumors.  It is also helpful in identifying the myoepithelial layer in breast tissue, and the basal layer in prostate tissue.

 

The combined expression of p63 and CK5 in poorly differentiated tumors is highly suggestive of squamous origin (Kaufmann, O., et al)

CK5 will stain approximately 70-80% of squamous cell carcinomas with a cytoplasmic staining pattern.  p63 is considered slightly more sensitive, but may give varying positivity in cases of lung adenocarcinoma that can be confusing.  Therefore, CK5 and p63 are often used as part of a panel to diagnose squamous cell carcinoma.  Since p63 is a nuclear marker, these two stains can be performed as a double stain on a single slide with one or two different chromogens.

CK5 is an excellent marker for the basal layer, and stains in a similar pattern to 34βE12.  Again, CK5 can be combined with p63, which also stains the basal layer of prostate glands.

 

Bladder

CK5 will stain the myoepithelial layer of breast tissue, but other markers such as smooth muscle myosin and calponin are typically used more commonly.  Basal-like breast carcinomas usually express CK5, especially with the monoclonal CK5 antibody compared to CK5/6 (Bhargava, R, et al).  Metaplastic/sarcomatoid breast carcinomas have also been reported to express CK5.

CK5 will stain the stratified squamous epithelium.  If there are cells in the squamous epithelium, which may be Paget cells or melanocytes, CK5 can be used along with CK7 or Melan A/HMB-45 to differentiate between odd appearing keratinocytes, Paget’s disease, or melanocytes.

There is occasionally discussion as to which is a better marker.  Some feel CK5/6 is a better marker since it has more than one cytokeratin in it’s cocktail.  However, there is a very strong consensus among pathologists who have used both that CK5 performs significantly better than CK5/6, and is therefore, the preferred antibody.  

 

Common expression patterns in carcinoma (Chu, PG, et al).

 

Note:  other references note a much higher + expression pattern in meotheliomas.  This may be dependent upon the mix of epithelial and sarcomatous variants.

Cyclin D1 (bcd-1) is most commonly used diagnostically for confirming the diagnosis of mantle cell lymphoma (positivity should be diffuse, but intensity may be variable).   It has also been described to be expressed in invasive breast carcinoma.  While it is generally considered a specific marker (given the differential diagnosis usually with CLL/SLL), and can also be expressed in plasma cell neoplasms (40%) and hairy cell leukemia (25%).  One can also often see focal nuclear expression in vascular endothelial cells and other stromal cells, which should not be interpreted as focal positivity.

 

Given the small but variable expression of CD23 between CLL/SLL and Mantle cell lymphoma, including CyclinD1 in the standard IHC panel for this differential is recommended.

Recently cyclin D1 expression in proliferation centers of cases of CLL/SLL have been described, which should not be confused with diffuse expression encountered in cases of mantle cell lymphoma. 

There are several clones available, but the most sensitive marker is the rabbit monoclonal antibody from Biocare Medical.  Other clones are not recommended.

Gradowski, J. F., Sargent, R. L., Craig, F. E., Cieply, K., Fuhrer, K., Sherer, C., & Swerdlow, S. H. (2012). Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma With Cyclin D1 Positive Proliferation Centers Do Not Have CCND1 Translocations or Gains and Lack SOX11 Expression. American Journal of Clinical Pathology, 138(1), 132–139. doi:10.1309/AJCPIVKZRMPF93ET

 

Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 221.

Chromogranin A is a very specific marker for neuroendocrine cell differentiation (reacts with cytoplasmic neurosecretory granules).  Unfortunately, it is not highly sensitive.  It is often used as part of a panel to identify neuroendocrine neoplasms (e.g. synaptophysin, CD56).  It is more often positive in well-differentiated lesions, and stains the neurosecretory granules in the cell cytoplasm.

 

Chromogranin A is expressed in approximately 30% of small cell carcinomas and neuroblastomas.

Wick, MR. “Immunohistochemical approaches to the diagnosis of undifferentiated malignant tumor.”Annals of Diagnostic Pathology12(2008):72-84.

CEA (carcinoembryonic antigen), CD66e, comes as either a polyclonal (pCEA) or monoclonal (mCEA) stain.  CEA is generally used as an epithelial marker with strong expression in adencarcinomas.  CEA is strongly expressed in colorectal adenocarcinomas, but it is not a specific marker as many other epithelial tumors may show expression.  CEA is most commonly used as part of a panel to discriminate between metastatic carcinoma (positive) and mesothelioma (negative).

Wick, MR. “Immunohistochemical approaches to the diagnosis of undifferentiated malignant tumor.”Annals of Diagnostic Pathology12(2008):72-84.