All posts by peferguson

Organ Systems

Kidney

Renal Cell Carcinoma
The use of IHC in the setting of renal cell carcinoma (RCC) usually falls into one of two categories: (1) carcinoma of unknown primary, or (2) differentiation of RCC subtypes.  Dependent upon which category one is in dictates what type of panel to utilize.
 
RCC vs. Other Malignancy
>80% expression in RCC
>80% expression in RCC
CK7/CK20
Both typically negative in clear cell RCC
>95% expressión in convencional clear cell RCC
>85% expression in clear cell and papillary subtypes
Variable but usually positive (author’s experience)
Positive
RCC Conventional Clear Cell type is one of a limited differential with co-expression of vimentin and cytokeratin.
RCC Subtype Differentiation
IHC may be helpful in sub-typing a RCC tumor.  This usually occurs in the setting of differentiating between a chromophobe RCC and a conventional clear cell RCC with eosinophilic cytoplasm.  The best way to confirm a clear cell RCC is to take more sections, and definitively identify clear cell areas.  Unfortunately, on small biopsies this may not be possible, and IHC provides helpful clues.
 
Negative in chromophobe RCC/oncocytoma, and >85%+ in clear cell RCC.
Usually expressed in most RCCs, but literature varies widely.  CAM5.2 probably better consistency and sensitivity.
>80% + in chromophobe RCC/oncocytoma, and negative (<5%+) in clear cell RCC.
Oncocytomas are usually negative for CK7, while chromophobe RCC is often positive.
Almost all oncocytomas and chromophobe RCCs show expression of E-Cadherin.  Clear cell and papillary RCCs are typically negative.  Xp11.2 translocation RCC are usually positive.
TFE3 is a specific marker for Xp11.2 translocation renal cell carcinomas, and is expressed in >90% of such cases.
 
As a general rule of practice in IHC, it is best to have both positive and negative markers for differentiation. 
 
IHC Stain
RCC
Clear Cell
RCC
Papillary
RCC
Chomophobe
RCC
Xp11.2
94-100%
67-93%
+/- 0-72%
+ >90%
0-37%
80-87%
73-86%
17%
=
=
=
N/A
35% (varies)
82%
16%
11%
87%
100%
=
66%
92%
87%
+/- 0-82%
 
98%
87%
83%
 
72-85%
87-95%
0-91%
 
0-5%
0-13%
82-100%
 
88%
>90%
>90%
 
Negative
Negative
Positive
68%
 
AE1/AE3 has varying positivity in the literature.  Part of this is probably due to that AE1/AE3 lacks CK18, which is expressed by most RCCs.  Other CKs have varying expression.  CAM5.2 is recommended over AE1/AE3.
Differential Diagnosis
Adrenocortical Carcinoma: AE1/AE3 -, EMA -, RCC Ma., Inhibit +, Calretinin +
 
Angiomyolipoma:  MART-1 +, HMB-45 +, Tyrosinase +, Smooth Muscle Markers +, Cytokeratins -, EMA –
Photomicrographs
Chomophobe Renal Cell Carcinoma
Chromophobe renal cell carcinoma with perinuclear halos, oncocytic features, and scattered vegtable-like cells.
Chromophobe Renal Cell Carcinoma
Chromophobe renal cell carcinoma with perinuclear halos, oncocytic features, and scattered vegtable-like cells.
Chomophobe Renal Cell Carcinoma - E-Cadherin
E-Cadherin expression in a chromophobe RCC.
Chromophobe Renal Cell Carcinoma - CD117
CD117 expression in a chromophobe RCC.
References
 Arch Path Lab Med – Vol. 135, Jan. 2011 (Truong & Shen).
 
Pan, CC. “Differential Immunoprofiles of Hepatocellular Carcinoma, Renal Cell Carcinoma, and Adrenalcortical Carcinoma.” Appl Immunohistochem Mol Morphol. Vol. 13, No. 4, Dec. 2005.
 
Diagnostic Immunohistochemistry: Theranostic and Genomic Applications. [edited by] DJ Dabbs. 3rd Edition.  Elsevier, 2010.
 
Shen, SS. “Role of Immunohistochemistry in Diagnosing Renal Neoplams: When Is It Really Useful?”Arch Pathol Lab Med, Vol. 136, April 2012.  pp. 410-417. 
 
Camparo, P., Vasiliu, V., Molinie, V., Couturier, J., Dykema, K. J., Petillo, D., et al. (2008). Renal translocation carcinomas: clinicopathologic, immunohistochemical, and gene expression profiling analysis of 31 cases with a review of the literature. The American Journal of Surgical Pathology, 32(5), 656–670. doi:10.1097/PAS.0b013e3181609914
 
 
 
 
 
Antibody List, N - Z Antibodies

Vimentin

Vimentin is an intermediate filament found in mesenchymal tissue.  It is not a specific stain and there is a subset of tumors which characteristically have co-expression of cytokeratin and vimentin.  It should also be noted that poorly differentiated carcinomas of any origin may express vimentin.  
 
Some pathologists joke they use vimentin to see if IHC stains will even work in a particular piece of tissue, but vimentin can be very helpful especially when used in conjunction with a panel of stains.
Carcinomas with co-expression of vimentin
  • Renal Cell Carcinoma
  • Thyroid Carcinoma (Papillary & Anaplastic)
  • Endometrial Adenocarcinoma
  • Sarcomatoid Carcinoma
  • Mesothelioma (biphasic)
  • Metaplastic Breast Carcinoma
  • Myoepithelial Carcinoma
Sarcomas with co-expression of cytokeratin
  • Desmoplastic Small Round Cell Tumor
  • Epithelioid Sarcoma
  • Epithelioid Angiosarcoma
  • Malignant Rhabdoid Tumor
  • Synovial Sarcoma
  • Leiomyosarcoma
  • Chordoma
  • Adamantinoma
Photomicrographs
Vimentin - Renal Oncocytoma
Vimentin highlighting vessels around nest of tumor cells in a renal oncocytoma.
Vimentin - Renal Cell Carcinoma
Vimentin expression in renal cell carcinoma
Renal Cell Carcinoma - Vimentin
Vimentin expression in a recurrent renal cell carcinoma
Vimentin - Colon Adenocarcinoma
Vimentin expression expressed in stromal tissue surrounding colon adenocarcinoma epithelium.
References
Kandukuri SR, Lin F, Gui L, Gong Y, Fan F, Chen L, et al. Application of Immunohistochemistry in Undifferentiated Neoplasms: A Practical Approach. Arch Pathol Lab Med. 2017;141: 1014–1032. doi:10.5858/arpa.2016-0518-RA
CD Markers, Antibody List

CD21

CD21 is a follicular dendritic cells (FDC) marker.  It has a membranous staining pattern, but this is practically difficult to separate from a cytoplasmic pattern in lymphoid tissue.  This stain is most often used as an “architectural” marker or aberrant patterns (nodular lymphocyte predominate Hodgkin lymphoma).  There are some rare tumors of FDC, which will mark with CD21.  CD21 may rarely mark normal B-cells, and strong expression of CD21 in CLL has been associated with a most aggressive disease course (unsure if this is by flow cytometry and/or IHC). 
 
Follicular Lymphoma – It is also helpful to identify the expanded follicular dendritic meshwork in cases of follicular lymphoma (especially helpful in diagnostically challenging cases – i.e. identifying a follicular component in an otherwise diffuse process or in small needle biopsies where architecture may not be visible).
 
Angioimmunoblastic T-cell Lymphoma (AILT) – Extrafollicular dendritic cells in the paracortical region in associated with neoplastic T-cells and high endothelial venules is characteristic of AILT.  CD21 is a helpful marker to highlights the follicular dendritic component in this process.
 
Marginal Zone Lymphoma – CD21 is useful in highlighting follicular colonization by marginal zone cells, which may be obscured by morphology alone.
CD21 Normal Expression Pattern
  • Follicular Dendritic Cells
  • Rare Normal B-cells
  • Rare cases of CLL
  • Generally thought of as a better follicular dendritic marker compared to CD23 (less sensitive)
Photomicrographs
CD21 - Tonsil
CD21 highlighting the follicular dendritic meshwork in benign tonsil tissue.
References
Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 64.
 
MD DY-PW, BacSc F.  A case of t (14; 18)-negative follicular lymphoma with atypical immunophenotype: usefulness of immunoarchitecture of Ki67, CD79a and follicular dendritic cell meshwork in making the diagnosis.  Malaysian Journal of Pathology. 2014. p. 125-129.
 
Harris NL, Swerdlow SH, Jaffe ES, et al. FollicularLymphoma. In: Swerdlow SH, Campo E, Harris NL,Jaffe ES, Pileri SA, Stein H, Thiele J, VardimanJW, editors. WHO classication of tumours of haematopoietic and lymphoid tissues. 4th ed. Lyon: IARC Press; 2008. p. 220–6.
 
Troxell ML, Schwartz EJ, van de Rijn M, Ross DT, Warnke RA, Higgins JP, et al. Follicular dendritic cell immunohistochemical markers in angioimmunoblastic T-cell lymphoma. Appl Immunohistochem Mol Morphol. 2005;13: 297–303.
 
Boyd SD, Natkunam Y, Allen JR, Warnke RA. Selective immunophenotyping for diagnosis of B-cell neoplasms: immunohistochemistry and flow cytometry strategies and results. Appl Immunohistochem Mol Morphol. 2013;21: 116–131. doi:10.1097/PAI.0b013e31825d550a
CD Markers, Antibody List

CD33

CD33 (gp67 and p67) is a specific hematopoietic marker, which is expressed in monocytes/macrophages, granulocyte precursors (decreases with maturation), mast cells, and dendritic cells.
 
Diagnostically, CD33 is helpful in differentiating myeloid tumors for lymphoid neoplasms.  Myelomonocytic and monoblastic leukemias may mark with CD33, but are usually negative for myeloperoxidase (MPO).  Hematodermic neoplasm is also negative for CD33.
References
 
Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 84.
CD Markers, Antibody List

CD43

CD43 is a pan T-cell marker, which is also expressed in myeloid (granulocytic) sarcomas and some B-cell lymphomas.  CD43 is aberrantly expressed in a number of B-cell lymphomas (expression is highly correlated with CD5), but this marker is most helpful in cases of marginal zone lymphoma when flow cytometry is not performed (i.e. usually small mucosal biopsies).  These cases may be difficult to differentiate from lymphoid hyperplasia.  Approximately 50% of cases of marginal zone lymphoma will express CD43.  Negativity for CD43 does not exclude the diagnosis, and additional molecular testing may be helpful to identify these cases.
 
Lee et. al identified normal co-expression of CD43 (strong expression) in perifolliuclar B-cells within submucosal lymphoid tissue from terminal ileum biopsies.  Therefore, CD43 co-expression on terminal ileum biopsies should NOT be used as a criterion alone to favor a diagnosis of MALT lymphoma.
 
The main take home point is that CD43 is a good marker, which is helpful, but there is lack a specificty and one should understand the stain performance in the diagnostic setting.  In the workup of a mature B cell lymphoma, CD43 (like CD5) should be compared against CD3 and CD20 staining.
 
CD43 Expression in Non-Hodgkin Lymphoma (Lai R., et. al. N=742 cases)
Diagnosis
CD43 Expression (%)
>90%
>90%
>90%
>90%
20-40%
20-40%
20-40%
Burkitt-Like B-Cell Lymphoma
20-40%
20-40%
0-6%
0-6%
 
In the skin CD43 marked >95% of cases of granulocytic sarcoma (leukemia cutis). Other non-T cell lesions which may stain with CD43 include:  AML, hemangioma, Langerhans cell histiocytosis, mast cell disease and plasmacytoma.
Photomicrographs
CD43 - Mantle Cell Lymphoma
Aberrant CD43 expression in mantle cell lymphoma.
References
Lai, R., Weiss, L. M., Chang, K. L., & Arber, D. A. (1999). Frequency of CD43 expression in non-Hodgkin lymphoma. A survey of 742 cases and further characterization of rare CD43+ follicular lymphomas. American Journal of Clinical Pathology, 111(4), 488–494.
 
Treasure, J., Lane, A., Jones, D. B., & Wright, D. H. (1992). CD43 expression in B cell lymphoma. Journal of Clinical Pathology, 45(11), 1018–1022. 
 
Cronin, D. M. P., George, T. I., & Sundram, U. N. (2009). An updated approach to the diagnosis of myeloid leukemia cutis. American Journal of Clinical Pathology, 132(1), 101–110. doi:10.1309/AJCP6GR8BDEXPKHR 
 
Jung G, Eisenmann J-C, Thiébault S, Hénon P. Cell surface CD43 determination improves diagnostic precision in late B-cell diseases. Br J Haematol. 2003;120: 496–499.
 
Lee P-S, Beneck D, Weisberger J, Gorczyca W. Coexpression of CD43 by benign B cells in the terminal ileum. Appl Immunohistochem Mol Morphol. 2005;13: 138–141.
 
Diagnostic Immunohistochemistry:  Theranostic and Genomic Applications [edited by] David J. Dabbs. 3rd Edition.  pp. 165.
CD Markers, Antibody List

CD45

CD45 (LCA) is also known as leukocyte common antigen (LCA).  It is a sensitive marker for lymphoid cells.  In the most general form it is often used as part of a panel for undifferentiated tumors or so-called “small round blue cell tumors.”  Such a screening panel usually includes: 
  • CD45 (lymphoid)
  • AE1/AE3 (carcinoma/epithelial) 
  • S-100 (neural/melanocytic)
  • Desmin (sarcoma/muscular origin)
  • CD99 (PNET if other markers are negative).
The biggest pitfall is to remember that CD45 is not perfectly sensitive.  Anaplastic large cell lymphoma (ALCL) may not express CD45 in 1/4th to 1/3rd of cases.  Classical Hodgkin Lymphoma cells are “classically” negative for CD45.  Mature plasma cells/plasma cell neoplasms are usually negative for CD45 (CD138 will also stain epithelial cells in addition to plasma cells).
Photomicrographs
CD45 - Classical Hodgkin Lymphoma
Loss of CD45 expression in Hodgkin cells in a case of nodular sclerosing classical Hodgkin lymphoma (CHL).
CD45 - Non-Hodgkin Lymphoma
Strong diffuse expression of CD45 in a non-Hodgkin lymphoma.
References
Wick, MR. “Immunohistochemical approaches to the diagnosis of undifferentiated malignant tumor.”Annals of Diagnostic Pathology12(2008):72-84.
 
Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 97.
CD Markers, Antibody List

CD56

CD56 (NCAM – neural-cell adhesion molecule) is expressed on the surface of neuroendocrine epithelial cells, some Schwann cells, and some neuroendocrine tumors.  In undifferentiated tumors, CD56 can be used as a screening marker for neuroendocrine differentiation.  It appears to be more sensitive than synaptophysin or chromogranin A in most situations, but Ishida, et. al found CD56 to be the least sensitive of the three in neuroendocrine carcinomas of the stomach (47% compared to 94% and 86% for synaptophysin and chromogranin A, respectively).
 
CD56 also marks a subset of hematopoeitic and gonadal-stromal cells.  Expression of CD56 alone should does not have significant specificity.
 
CD56 Sensitivity for high grade neuroendocrine tumors
  • Stomach – 47% (Ishida, et. al)
  • Esophagus – 93% (Huang, et. al)
  • Lung – >90% (Travis, et. al)
Hematopathology
Other
Basal cell carcinomas (BCC) show strong membrane and less intense cytoplasmic staining with CD56.  Important not to use with the differential diagnosis of merkel cell carcinoma.  Squamous cell carcinomas (SCC) do not express CD56, and in the BCC vs. SCC differential CD56 may be helpful.
CD56 Expression Pattern – Other
  • BM Osteoblasts
  • Neuroendocrine Neoplasms
  • Basal cell carcinoma
Photomicrographs
CD56 - NK Cell Lymphoma
CD56 expression in a NK-cell lymphoma.
CD56 - Small Cell Carcinoma
CD56 expression in small cell carcinoma.
CD56 - Merkel Cell Carcinoma
CD56 expression in Merkel cell carcinoma
CD56 - Basal Cell Carcinoma
CD56 expression in a subset basal cell carcinoma tumor cells.
References
Cronin DMP, George TI, Sundram UN. An updated approach to the diagnosis of myeloid leukemia cutis. Am J Clin Pathol. 2009;132: 101–110. doi:10.1309/AJCP6GR8BDEXPKHR
 
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
 
Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 104.
 
Ishida M, Sekine S, Fukagawa T, Ohashi M, Morita S, Taniguchi H, et al. Neuroendocrine carcinoma of the stomach: morphologic and immunohistochemical characteristics and prognosis. Am J Surg Pathol. 2013;37: 949–959. doi:10.1097/PAS.0b013e31828ff59d
 
Huang Q, Wu H, Nie L, Shi J, Lebenthal A, Chen J, et al. Primary high-grade neuroendocrine carcinoma of the esophagus: a clinicopathologic and immunohistochemical study of 42 resection cases. Am J Surg Pathol. 2013;37: 467–483. doi:10.1097/PAS.0b013e31826d2639
 
Cronin DMP, George TI, Reichard KK, Sundram UN. Immunophenotypic analysis of myeloperoxidase-negative leukemia cutis and blastic plasmacytoid dendritic cell neoplasm. Am J Clin Pathol. 2012;137: 367–376. doi:10.1309/AJCP9IS9KFSVWKGH
 
Bénet C, Gomez A, Aguilar C, Delattre C, Vergier B, Beylot-Barry M, et al. Histologic and immunohistologic characterization of skin localization of myeloid disorders: a study of 173 cases. Am J Clin Pathol. 2011;135: 278–290. doi:10.1309/AJCPFMNYCVPDEND0
 
Joshi R, Horncastle D, Elderfield K, Lampert I, Rahemtulla A, Naresh KN. Bone marrow trephine combined with immunohistochemistry is superior to bone marrow aspirate in follow-up of myeloma patients. J Clin Pathol. 2008;61: 213–216. doi:10.1136/jcp.2007.049130
 
Seegmiller AC, Xu Y, McKenna RW, Karandikar NJ. Immunophenotypic differentiation between neoplastic plasma cells in mature B-cell lymphoma vs plasma cell myeloma. Am J Clin Pathol. 2007;127: 176–181. doi:10.1309/5EL22BH45PHUPM8P
 
BELJAARDS RC, KIRTSCHIG G, BOORSMA DM. Expression of neural cell adhesion molecule (CD56) in basal and squamous cell carcinoma. Dermatol Surg. 2008;34: 1577–1579. doi:10.1111/j.1524-4725.2008.34327.x
 
Herling M, Jones D. CD4+/CD56+ hematodermic tumor: the features of an evolving entity and its relationship to dendritic cells. Am J Clin Pathol. 2007;127: 687–700. doi:10.1309/FY6PK436NBK0RYD4
 
Travis WD. Update on small cell carcinoma and its differentiation from squamous cell carcinoma and other non-small cell carcinomas. Mod Pathol. Nature Publishing Group; 2012;25: S18–S30. doi:10.1038/modpathol.2011.150
CD Markers, Antibody List

CD68

CD68 (gp110) is a glycosylated lysosomal transmembrane glycoprotein, which is normally expressed on monocytes, macrophages, dendritic cells, neutrophils, basophils, myeloid progenitor cells, mast cells, activated T-cells, and a subset of blasts.  The staining pattern is generally cytoplasmic.  Almost all MPO+ bone marrow cells will express CD68.
 
In the setting of leukemia cutis, CD68 was expressed in >95% of cases (Benet, et. al).  Typically, CD68 is used to identify histiocytes.  Unfortunately, CD68 lacks specificity and the morphologic differential diagnosis overlaps in many situations, and use as part of a larger panel yields more specific results.
 
CD68R (PGM-1) is one of the epitopes of CD68, and appears to be the most monocyte specific marker of the CD68 family.  Expression in monocytic differentiated AMLs is reported to be 92-94% (Rollins-Raval, et. al)
Photomicrographs
CD68 - Ovary histiocytes
H&E section of ovary showing histiocytes.
CD68 - Ovary histiocytes
CD68 staining histiocytes in ovarian parenchyma with physiologic type changes.
CD68 - Ovary histiocytes
High power view of ovary parenchyma with histiocytes (physiologic changes).
CD68 - Tonsil
CD68 highlighting scattered macrophages in benign tonsil.
References
Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 114.
 
Bénet C, Gomez A, Aguilar C, Delattre C, Vergier B, Beylot-Barry M, et al. Histologic and immunohistologic characterization of skin localization of myeloid disorders: a study of 173 cases. Am J Clin Pathol. 2011;135: 278–290. doi:10.1309/AJCPFMNYCVPDEND0
 
Cronin DMP, George TI, Sundram UN. An updated approach to the diagnosis of myeloid leukemia cutis. Am J Clin Pathol. 2009;132: 101–110. doi:10.1309/AJCP6GR8BDEXPKHR
 
Rollins-Raval MA, Roth CG. The value of immunohistochemistry for CD14, CD123, CD33, myeloperoxidase and CD68R in the diagnosis of acute and chronic myelomonocytic leukaemias. Histopathology. 2012;60: 933–942. doi:10.1111/j.1365-2559.2012.04175.x
CD Markers, Antibody List

CD71

CD71 is one of the most useful, but least used antibodies in hematopathology.  CD71 is an integral membrane protein, which is involved in the uptake of the transferrin-iron complex.  Immunoreactivity is restricted to erythroid precursors with a membranous and cytoplasmic stain pattern.
 
Previously there have been other erythroid markers, but they have been difficult to interpret because they stain all RBCs and precursors.  CD71 stains immature erythroid precursors, which are nucleated, and is not significantly expressed in mature RBCs.  The utility of CD71 is to help differentiate between normoblasts and myeloblasts in bone marrow specimens.  This is especially powerful when combined with CD34 (sensitive/not specific myeloblast marker) on a dual staining IHC platform (red and DAB chromogens).
 
CD71 can be a particularly useful tool to help accurately characterize immature cellular elements in bone marrow specimens, and decrease misidentification of normoblasts for myeloblasts and/or ALIP.  E-Cadherin will also stain immature erythroid precursors (usually in a dimmer pattern compared to CD71).
 
Utilization of CD71 in gestational pathology has found it to be helpful to identify nucleated red blood cells (NRBCs) in partial molar pregnancies and spontaneous abortions in contrast to complete moles (absence of NRBCs). 
 
Dim staining is expected in lymphoid cells (significantly different from nucleated red cell precursors), which can serve as a nice control (e.g. tonsil tissue).
Photomicrographs
Lymphoid aggregate with dim CD71 expression (erythroid precursors at the periphery). Can be useful as a control (e.g. tonsil).
CD34-CD71 Double Stain AML
CD34 (red) and CD71 (brown) double stain in a case of acute myelogenous leukemia (AML).
CD71 - Normal Bone Marrow
CD71 highlighting erythroid precursors in a normal bone marrow sample.
References
Marsee, D. K., Pinkus, G. S., & Yu, H. (2010). CD71 (transferrin receptor): an effective marker for erythroid precursors in bone marrow biopsy specimens. American Journal of Clinical Pathology, 134(3), 429–435. doi:10.1309/AJCPCRK3MOAOJ6AT
 
Dong, H. Y., Wilkes, S., & Yang, H. (2011). CD71 is Selectively and Ubiquitously Expressed at High Levels in Erythroid Precursors of All Maturation Stages: A Comparative Immunochemical Study With Glycophorin A and Hemoglobin A. The American journal of surgical pathology, 35(5), 723–732. doi:10.1097/PAS.0b013e31821247a8 
 
Luchini C, Parcesepe P, Nottegar A, Parolini C, Mafficini A, Remo A, et al. CD71 in Gestational Pathology: A Versatile Immunohistochemical Marker With New Possible Applications. Appl Immunohistochem Mol Morphol. 2016;24: 215–220. doi:10.1097/PAI.0000000000000175
 
Acs G, LiVolsi VA. Loss of membrane expression of E-cadherin in leukemic erythroblasts. Arch Pathol Lab Med. 2001;125: 198–201. doi:10.1043/0003-9985(2001)125<0198:LOMEOE>2.0.CO;2
 
Sadahira Y, Kanzaki A, Wada H, Yawata Y. Immunohistochemical identification of erythroid precursors in paraffin embedded bone marrow sections: spectrin is a superior marker to glycophorin. J Clin Pathol. 1999;52: 919–921.
CD Markers, Antibody List

CD79a

CD79a (MB1) is a B-cell marker with a wider range of positivity in the B-cell development spectrum compared to CD20 (mature B-cell phenotype).  CD79a may be expressed on malignant precursor B-cells and terminally differentiated B-cells (PAX-5 is not expressed in terminally differentiated B-cells).  Please note that in the setting of ALL, CD79a is not lineage specific, and up to 50% of T-ALL cases express CD79a.  AML cases with t(8;21) may also show CD79a expression (along with CD19, CD20, and TdT).

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