A cell surface-associated protein found on most thymocytes and immature peripheral T-cells, but not in NK cells. It stains normal B-cells of mantle zone of spleen and lymph nodes, B-cells in peritoneal and pleural cavities, and almost all T-cells. It shows aberrant expression by two B cell neoplasms, chronic lymphocytic leukemia/small lymphocytic lymphoma and mantle cell lymphoma, as well as hairy cell leukemia, most T-malignancies, and most thymic carcinomas. CD5 is usually negative in spindle cell thymona, while in a fetus, most B-cells in spleen and cord blood are CD5 positive.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen typeorOne (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody orderedBlock and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.