CD20 Positive T Cell Lymphoma

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T-cell Lymphomas describe a diverse group of blood cancers that originate from T-cells.  However, CD20 expression in T Cell Lymphoma is a rare occurence that has been reported in literature.

Sample Cases

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Case Name (click to open) Comments Size
CD20PosTL.fey  CD20+ t cell lymphoma showing aberrant T cell expression with dim CD20 expression.  Special Thanks to Carol Moore for providing the data files! 6.23 MB

Generally, T cell Lymphoma is uncommon, occurring in about 10% of all non-Hodgkins Lymphomas.  CD20 positive t cell lymphoma represents a small fraction of t cell lymphomas.  It is more common in adults than children.Epidemiology

Possible Causes

The pathogenesis of CD20+ T cell lymphoma is not known.  CD20 is a transmembrane protein that was first identified as a B cell marker in 1980.  CD20 appears early in B cell development and remains present through the Plasma Cell stage of development.  Hultin and colleagues have described dim CD20 expression on normal T cells in some individuals.  It is possible that the CD20+ T cell lymphoma arises from this subpopulation of normal T cells that have undergone a neoplastic transformation.


According to the literature, all the cases in the study presented with a hypercellular marrow with interstitial lymphocytic infiltrates.  The infiltrating lymphocytes were small to medium-sized with a small amount of cytoplasm, slightly irregularly shaped nuclei and inconspicuous nucleoli.

Morphology of CD20+ T cell Lymphoma


The immunophenotype of CD20 positive T Cell Lymphoma is similar to other T cell malignancies, except for the presence of the CD20 protein.  These neoplasms typically express CD2, CD4, CD5, CD8 and with varying degrees of CD7 and a decrease or absence of CD3 expression.

In this case, the Lymphocytes show a predominant population with dim CD20 expression, while being negative for CD19. The Lymphocytes also show a population of T Cells that express CD7, but not CD3.  These same cells also co-express CD2. A CD8 dim population is apparent.


Imai M, Jiang JG, Wu Z, Dabbas B, Ni H.  "CD20-positive T-cell lymphoma involving bone marrow:  report of four cases"  Journal of Hematopathology, ISSN 1868-9256, 26 February 2013.  DOI 10.1007/s12308-013-0177-9


Sun T, Akalin A, Rodacker M, Braun T.  "CD20 positive T cell lymphoma:  is it a real entity?"  Journal of Clinical Pathology 2004 April; 57(4):  442-444.  DOI 10.1136/jcp.2003.011734


Buckner C, Christiansen L, Bourgeois D, Lazarchick JJ, Lazarchick J.  "Case Reports:  CD20 Positive Lymphoma/Leukemia:  A Rare Entity with Diagnostic Pitfalls" Annals of Clinical and Laboratory Science, vol 37, no. 3, 2007:  263-267