Despite their postulated origin from postgerminal center B cells, primary effusion lymphoma cells are negative for B-cell markers such as CD19, CD20, and CD79a
Aberrant expression of CD7, CD56, and CD79a
antigens in acute myeloid leukemia.
3) Tumors express various pan B-cell markers such as CD19, CD20 (Figure 2, A), CD22, and CD79a
, but may lack one or more of these.
One of the most consistent and striking features of PBL is a marked decrease in the expression of B-lineage antigens, including CD20, CD79a
, and PAX5.
At the US reference facility, The Ohio State University Comprehensive Cancer Center Pathology Core Research Laboratory (Columbus, Ohio), thin sections (4-[micro]m thick) of the tissue microarray were cut and stained with hematoxylin-eosin and monoclonal antibodies by immunohistochemistry against CD3, CD15, CD20, CD30, CD34, CD43, CD44, CD45, CD45RO, CD68, CD79a
, CD138, Bcl-2, Bcl-6, immunoglobulin M (IgM), Ki-67, MUM-1, TdT (DAKO, Carpinteria, California), CD5, and CD10 (Novocastra, Bannockburn, Illinois); in situ hybridization Epstein-Barr virus, [kappa] and [lambda] light chains, and dual-color c-MYC gene break apart probe fluorescent in situ hybridization (FISH) FISHba c-MYC t(8;14) (Abbot/Vysis, Downer's Grove, Illinois).
By immunohistochemistry, the neoplastic cells are commonly positive for B-cell antigen markers, including CD20 (Figure 2, C) and CD79a
As with low-grade nodal FL, most GI FLs express Bcl-2 and pan B-cell markers such as CD20 and CD79a
For B-cell markers, HRS cells are positive for CD20 on a minority of the neoplastic cells with varied intensity in 30-40% of cases, CD79a
is less often expressed.
Immunophenotypic classification of canine malignant lymphoma on formalin-fixed paraffin wax-embedded tissue by means of CD3 and CD79a
Immunohistochemistry revealed positive staining of the tumor cells for CD43 and myeloperoxidase (negative for CD20, CD79a
, CD30, CD99, CD3, CD138, AE1/3 and Cam 5.
The neoplastic lymphoid cells were positive for CD20 and CD79a
but negative for CD3, CD4, CD5, CD8, CD10, CD30 and Bcl-2.
Markers that were negative (0%) included CD30 (n = 6), [kappa] light chain (n = 2), [lambda] light chain (n = 2), CD8 (n = 2), CD1a (n = 1), CD2 (n = 1), CD5 (n = 1), CD7 (n = 1), CD15 (n = 1), CD45RO (n = 1), CDw75 (n = 1), CD79a
(n = 1), CD123 (n = 1), CD138 (n = 1), PAX5 (n = 1), TCL-1 (n = 1), and anaplastic lymphoma kinase (ALK; n = 1).