Utility of immunohistochemistry on bone marrow trephine biopsy for the diagnosis and classification of acute leukemia

Background: Bone marrow examination is an essential diagnostic tool in acute leukemia for the determination of lineage of blasts by flow cytometry or immunophenotyping. In cases of dry tap or where facilities of flow cytometry is not available, immunohistochemistry (IHC) on trephine biopsy sections can be used as a supportive tool to diagnose and classify acute leukemia. Materials and Methods: The giemsa-stained peripheral smears and bone marrow aspirate/imprints smears were retrospectively evaluated. IHC was done on trephine biopsy sections using a panel of antibodies which included CD34, MPO, CD117, Tdt, CD3, CD20, PAX5, and CD10 Results: Of the 29 cases diagnosed by IHC on trephine sections, 25 cases could be accurately classified based on the expression of myeloid and lymphoid markers. Majority of the acute lymphoblastic leukemia (ALL) were of B-cell lineage (81.25%), and almost half of the B-ALL were common acute lymphoblastic leukemia-associated antigen positive. Conclusion: IHC on trephine biopsy facilitates the confirmation and subtyping of leukemia in more than 85% cases. A limited panel of antibodies using CD34, MPO, TdT, CD3 CD20, PAX 5, and CD10 can be used for subtyping of leukemias in trephine biopsy sections, especially in centers with limited resources. It obviates the need for a repeat bone marrow procedure where material is not available for flow cytometry.