Aberrant expression of multiple T antigens: CD4, CD5, and CD8 on diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. Aberrant expression of T antigens (exclusive of CD5) in DLBCL has been described in the literature; however, coexpression of 2 or more T antigens is rare. We report a case with a well-established diagnosis of DLBCL, coexpressing 3 T-cell antigens, CD4, CD5, and CD8. Although the clinical significance of T antigen coexpression in DLBCL is unclear, it is important to be aware of such phenotypic plasticity to ensure accurate diagnoses are made. The expression of multiple T-cell antigens may introduce diagnostic confusion and make subclassification of a lymphoma using World Health Organization criteria difficult.