ALK - tyrosine kinase receptor

Fusion protein expressed only by lymphomatous cells

Stains ALCL and rare subsets of DLBCL.  Hodgkin's lymphoma is negative.

bcl-2

Inhibits apoptosis, and normally turns off in a germinal center (membranous and cytoplasmic stain).

To differentiate follicular lymphoma (positive) from reactive follicles (negative).  Also stains mantle cell lymphoma.  Burkitt's lymphoma should be negative.

bcl-6

Present on germinal center cells including follicular center B cells, follicular center T-helper cells. (cytoplasmic).

To identify lymphomas of follicular origin (FCC, Burkitt's lymphoma).  Also stains angioimmunoblastic T-cell lymphoma and anaplastic large cell lymphoma.

CD1a

Thymocytes (immature T cells) and Langerhans cells (membranous)

To identify Langerhans cell proliferations, (T-LBL).

CDs 3, 4, 5, 7, 8

T cells.

To identify T-cell lymphomas and leukemias; CD4 is also dimly positive in monocytic/histocytic lesions.

CD10 - CALLA

A zinc metalloproteinase normally expressed by precursor B and T helper cells in follicular centers, granulocytes (membranous).

Stains follicular lymphoma, B-ALL, LBL (lymphoblastic lymphomas), Burkitt's lymphoma, angioimmunoblastic T cell lymphoma, and CML; MALTomas are negative.

CD10 positivity indicates follicular center origin.

CD20

Calcium channel normally expressed by B cells (cytoplasmic and membranous). Doesn't stain plasma cells.

Used as a pan-B-cell marker; stains B-cell lymphomas, but plasmacytomas are negative.

Also stains L&H cells in NLPHL.  Stains RS in 20% of classical Hodgkins

CD15 (Lewis^x trisaccharide)

Granulocytes and macrophages (membranous and dot-like perinuclear).

To identify Reed Sternberg cells (classic Hodgkins), some large T-cell lymphomas, and mycosis fungoides.

CD23 - low affinity receptor for IgE Fc on the surface of B cells.  Upregulated by EBV infection.

Activated mature B cells, IgE receptor (membranous).

Stains SLL/CLL; mantle cell lymphomas are negative.

CD30 - TNF-like receptor

Present on activated B and T cells, immunoblasts, NK cells, and monocytes.  (cytoplasmic, membranous).

To identify Reed Sternberg cells, ALCL, large B and T cell lymphomas.

CD34

Pluripotent hematopoietic stems cells and progenitor cells of many lineages.  Hematolymphoid blasts, fibroblasts, and endothelial cells (cytoplasmic and membranous). 

To identify blasts in the marrow in acute leukemias; also many soft tissue tumors.

CD45 - Common Leukocyte Antigen.  It is a tyrosine phosphatase.

Lymphocytes, granulocytes, histiocytes, but not plasma cells (cytoplasmic, membranous).

To identify poorly differentiated neoplasms as of hematopoietic origin. 

RS cells and plasma cell neoplasms are negative for CD45.  Occasionally lymphoblastic and anaplastic large cell lymphomas are unreactive.

CD56 - NCAM-like adhesion.

Present on Natural killer cells (membranous).

Stains natural killer/T-cell lymphomas.

CD68

Histiocytes/macrophages/monocytes, granulocytes, others (cytoplasmic, membranous).

To identify histiocytic origin; also stains soft tissue tumors.

CD79a - part of the BCR complex.

B cells and plasma cells (membranous).

To identify B-cell neoplasms negative for other B-cell markers. Stains B-ALL, B lymphomas, and myelomas.

CD138 - heparin sulphate proteoglycan

Plasma cells (membranous), epithelial cells.

To identify plasma cell neoplasms.  Only stains abnormal B cells that have plasmocytic differentiation.

Cyclin D1 - G1/S cell cycle transition protein

Nuclear stain in mantle cell lymphoma.  Also stains endothelial cells and histiocytes.

To identify mantle cell lymphoma.

EBV RNA in infected B cells (nuclear).

To identify EBV related tumors, including nasopharyngeal carcinoma, posttransplantation/AIDS lymphomas; also mononucleosis.

FVIII/vWF

Stains megakaryocytes, platelets, and endothelial cells (cytoplasmic).

To identify megakaryocytic leukemias.

Hemoglobin in erythroid cells (cytoplasmic).

To identify erythroid leukemias (rare).

Kappa and lambda

Light chain of immunoglobulins in plasma cells and B cells (cytoplasmic).

Restricted kappa or lambda staining indicates a monoclonal population of B or plasma cells.

Ki67

Any proliferating cell (nuclear).

To gauge mitotic activity and identify Burkitt's lymphoma (100% positivity).

MPO

Enyzyme granules in myeloid-lineage cells (cytoplasmic).

To identify AML and myeloid sarcoma (chloroma).

TdT - antigen receptor gene modification.

Immature T and B lymphocytes (nuclear).

To identify LBL and ALL.

CD19

Associated with the BCR complex and normally expressed by Pre-B cells and mature B cells, but not plasma cells. 

Stains B cell lymphoma; B-lymphoblastic leukemia/lymphoma.

Repeat normal plasma cells are negative, but myeloma can abberantly express CD19.

CD21

EBV receptor; mature B cells and follicular dendritic cells.

CD11c

Granulocytes, monocytes, and macrophages; also expressed by hairy cell leukemias.

CD13

Immature and mature monocytes and granulocytes.

CD14

Monocytes

CD33

Myeloid progenitors and monocytes.

CD64

Mature myeloid cells.

CD3

Part of the TCR complex; present on normal T cells.

Stains T cell lymphoma. 

CD4

MHC class II co-receptor present on helper T cells and monocytes.

Stains T cell lymphoma. 

MHC x CD# = 8

CD5

Normally expressed on T cells and a subset of B cells.

Stains B-CLL/SLL and mantle cell lymphoma. 

CD7

Normally expressed on marrow stem cells; thymocytes; T cells.

Stains T lymphoblastic leukemia/lymphoma; often absent in T cell lymphoma. 

CD8

MHC class I co-receptor normally expressed on cytotoxic T cells and NK cells.

Stains T/NK lymphoma. 

PAX5 - B cell specific activator protein.

Present on B cells except plasma cells.

Stains B cell neoplasms including B-ALL.  Also stains L&H cells in NLPHL; Reed-Sternberg cells in classical Hodgkins stains moderate to weak.

CD22

Sialoconjugate receptor on B cells.

Stains B cell lymphoma.

CD25

IL-2 receptor alpha chain.

Present on activated T and B cells.  Also on monocytes.

Stains anaplastic large cell leukemia/lymphoma and hairy cell leukemia.

CD38 - NAD glycohydrolase.

Present on B cells, activated T cells, and plasma cells.

Stains plasma cell myeloma and lymphoplasmacytic lymphoma.

CD43 - leukosialin

Present on all lymphocytes other than resting B cells.

Stains B-CLL/SLL, mantle cell lymphoma, and MALT lymphoma.

CD57

Present on NK cells, monocytes, and subsets of B and T cells.

Stains T/NK cell leukemia/lymphoma.

CD103 - integrin

Present on a lymphocyte subset.

Stains hairy cell leukemia.

OCT-2

BOB.1

Present on B cells and plasma cells.

Stains B-cell neoplasms, including plasma cell and plasmablastic neoplasms.

Some T-cell lymphomas can be BOB.1 positive. 

MUM1/IRF4

Present on plasma cells and plasma blasts.  Also present on a subpopulation bcl6 follicular center B cells and a small percentage of activated T cells.

Stains plasma cell and plasma blastic neoplasms; lymphoplasmacytic lymphoma; diffuse large B-cell lymphomas (75%); other B and T-cell lymphomas (variable).

CD163

Scavenger receptor for hemoglobin-haptoglobin complex.  Haptoglobin binds free hemoglobin and is cleared by CD163 on reticuloendothelial cells to prevent damage to renal tubules.

CD163 is only present on monocyte/macrophage lineage.