Cd 5 Immunohistochemistry Bone Marrow

CD5 is expressed normally on all T cells one of the pan T-cell antigens. It can be aberrantly expressed by B-cell lymphomas (most commonly mantle cell lymphoma, B-cell small lymphocytic lymphoma). Expression of CD5 is useful to support T-cell lineage in T-cell lymphomas, or to help subclassify B-cell lymphomas. CD5 is a good immunohistochemical marker for T-cells, although not as sensitive as CD3. About 76% of T-cell neoplasms are reported to express CD5, and it is also found in chronic lymphocytic leukemia and mantle cell lymphoma both being B cell malignancies. It is commonly lost in cutaneous T-cell lymphoma, and its absence can be used as an indicator of malignancy in this condition. The absence of CD5 in T cell acute lymphoblastic leukemia, while relatively rare, is associated with a poor prognosis.