Useful Panel of Antibodies for the Classification of Acute Leukemia by lmmunohistochemical Methods in Bone Marrow Trephine Biopsy Specimens

Abstract

To evaluate the feasibility of acute leukemia typing on routinely processed bone marrow biopsy specimens, 72 cases of previously established acute leukemia covering the spectrum of 17 known subtypes were studied immunohistochemically. Most leukemic myeloblasts were positive for myeloperoxidase in 16 (84%) of 19 cases of acute myeloid leukemia, M1-M4, and M6. Most leukemic cells in 11 of 12 M4 and M5 cases were positive for CD68 (PG-M1). All six M6 cases stained with hemoglobin. Leukemic megakaryoblasts in three of four M7 cases were positive for factorThe diagnosis and classification of acute leukemia usually are made on the basis of examination of WrightGiemsa-stained smears of bone marrow aspirate or peripheral blood (or both) in conjunction with cytochemistry, immunocytochemistry, or immunophenotyping by flow cytometry. Bone marrow trephine biopsy is helpful in evaluating cellularity, fibrosis, megakaryocyte clustering, granulomas, and metastatic tumors. It rarely is used alone for the initial diagnosis and classification of acute leukemia. However, in certain situations, smears of peripheral blood or marrow aspirate are inadequate or not available for study, for example, a dry tap because of bone marrow fibrosis, hypocellular marrow aspirate (hypocellular acute leukemia), 1 technical problems, or the unexpected finding of acute leukemia. Thus, pathologists may need to rely on the paraffin blocks of bone marrow for the diagnosis and even classification of acute leukemia. Cell lineage-specific antibodies that can be applied to paraffin sections have become available during the last few years. Most of these antibodies have been evaluated individually for various types of acute leukemia. The number of reports on the use of these newly developed, commercially available cell lineage-specific antibodies to study immunohistochemically the entire subset of acute leukemia is small.2 ' 3The aims of this study were to evaluate how accurately subtyping of acute leukemia can be made on the basis of immunohistochemical studies performed on paraffin sections and to establish a practical costeffective immunohistochemical study for the diagnosis of the spectrum of acute leukemia. MATERIALS AND METHODSSeventy-two cases representing the entire subset of acute leukemia with cell lineage previously typed on the basis of cytochemical (Ml-5, AEol, ABaL) or immunocytochemical (M6-7) studies or immunophenotyping by flow cytometry (acute lymphoblastic leukemia [ALL], M0) of bone marrow aspirates were retrieved from the files of the Mayo Clinic, Rochester, Minn. These cases had been diagnosed and classified according to the French-American-British (FAB) C o o p e r a t i v e G r o u p c r i t e r i a .4 -8 L e u k e m i a s not defined by the FAB group were classified by other proposed criteria as acute eosinophilic leukemia 410

Acute panmyelosis with myelofibrosis: an entity distinct from acute megakaryoblastic leukemia

“…Since CD61 reacts poorly in B5-fixed and/or nitric acid decalcified bone marrow biopsies, vWF has usually been the antibody of choice, at least in the United States. 37,40 However, published evidence has shown that vWF expression is frequently decreased in cases of AMKL with poorly differentiated blasts, 6 a finding consistent with the decreased synthesis of alpha granules (where vWF is stored) in immature megakaryocytes.…”

“…[32][33][34][35] The identification of megakaryoblasts and atypical megakaryocytic forms can be greatly facilitated by the use of monoclonal antibodies reactive with platelet glycoproteins, such as CD41 (glycoprotein IIb/IIIa), CD42 (glycoprotein Ib), or CD61 (glycoprotein IIIa), or with a polyclonal antifactor VIII (vWF) antibody. [36][37][38][39] However, of the three antiplatelet glycoprotein antibodies, only CD42 and CD61 are demonstrable in routinely processed tissue sections. Since CD61 reacts poorly in B5-fixed and/or nitric acid decalcified bone marrow biopsies, vWF has usually been the antibody of choice, at least in the United States.…”

Immunohistochemical Detection of CD10 with Monoclonal Antibody 56C6 on Paraffin Sections

“…But in some cases, the ability to immunophenotype acute leukemias by these methods is markedly limited when blast cells are not present in the peripheral blood sample and when no bone marrow can be aspirated, for example, because of bone marrow fibrosis. In these cases MAb 56C6 should be H e m a t o p a t h o l o g y / ORIGINAL ARTICLE useful as part of a panel of paraffin-reactive antibodies against myeloperoxidase, CD68 (clone PGM-1), TdT, CD79a, and CD3 to differentiate AMLs from precursor B-ALLs, 8,9 as CD 10 usually is detectable in the latter, whereas CD 10 expression in AMLs is an exceptionally rare event. 3 However, for evaluating paraffin-embedded bone marrow biopsy specimens for primary or relapsing infiltrates of B-lineage ALLs using MAb 56C6, it is essential not to mistake nonneoplastic immature B-lineage lymphoid precursors expressing CD 10 (socalled hematogones) for neoplastic cells.…”

Diagnostic Approach in Acute Myeloid Leukemias in Line with WHO 2008 Classification

“…Myeloperoxidase is the most specific marker for assigning myeloid lineage ( Figure 7b); however, is negative in AML-M0 and blasts of monocytic, erythroid, and megakaryocytic lineages. Hemoglobin A1 and glycophorin A are positive in 90% to 100% of erythroid lineage cells, and FVIII is positive in 90% of megakaryocytic cells, but rare cases demonstrating inadequate lineage maturation (early megakaryoblasts) may be negative (Chuang SS & Li CY, 1997;Manaloor EJ, 2000 However, it is a challenge to interpret MPO negative AL cases. In such cases of AL, one has to first ensure that the B-and T-lymphoblastic lineages have been ruled out by a negative staining for CD79a, PAX-5, CD20, and CD3 (should detect CD3 epsilon chain and not zeta chain by a polyclonal antibody, which is non-specific) (Swerdlow SH et al, 2008).…”