Immunohistochemical detection of CD10 with monoclonal antibody 56C6 on paraffin sections

We tested a fetal of 174 paraffin-embedded hematolymphoid neoplasias to det ermine whether CD10 can be specifically and sensitively detected on paraffi n sections using monoclonal antibody 56C6 after epitope retrieval. Far 32 c ases, results of CD10 detection by immunohistochemistry were compared with flow cytometric data. In only 1 case of follicle center lymphoma, divergent staining results were found with the detection of CD10 by flow cytometry b ut not by immunohistochemistry. Altogether; 22 of 28 follicle center lympho mas, 2 of 6 hairy cell leukemias, 14 of 34 diffuse large B-cell lymphomas, 3 of 3 Burkitt lymphomas, 4 of 5 precursor B-lineage acute lymphoblastic le ukemias, and 2 of 4 T-lymphoblastic lymphomas were CD10(+). Decalcification of bone marrow biopsy specimens did not diminish the staining intensity. A ll other cases, including 10 acute myeloid leukemias and a range of low-gra de B-cell lymphomas, were CD10(-). CD10 is reliably detectable with antibod y 56C6 on paraffin sections using epitope retrieval. The antibody is especi ally useful for the subclassification of acute leukemias and low-grade B-ce ll lymphomas.