What does “CD5-positive lymphoma” mean?

Generally, CD5-positive lymphoma refers to the detection of CD5 antigen expression on the surface of lymphoma cells. A detailed analysis follows:

CD5 is a glycoprotein expressed on the surface of certain lymphocytes. Under normal physiological conditions, it is predominantly expressed on T lymphocytes and a subset of B lymphocytes. In lymphomas, CD5 positivity carries diagnostic and prognostic significance. For instance, in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), CD5 positivity is one of its characteristic immunophenotypic features, aiding differentiation from other types of B-cell lymphomas. Additionally, mantle cell lymphoma is typically CD5-positive. Generally, CD5-positive lymphomas may exhibit distinct biological behavior and treatment responses compared with CD5-negative lymphomas; some studies suggest they may display more aggressive clinical features. However, definitive conclusions require comprehensive evaluation incorporating additional clinicopathological parameters.

CD5 positivity in lymphoma is an important immunohistochemical marker with significant value for lymphoma classification, diagnosis, and prognostic assessment—though interpretation must be performed by experienced clinicians integrating multiple clinical and pathological factors.