Acute erythroid leukemia with <20% bone marrow blasts is clinically and biologically similar to myelodysplastic syndrome with excess blasts

Abstract

In acute erythroleukemia, erythroid/myeloid subtype, blasts usually comprise 5-19% of total bone marrow cells, similar to the myelodysplastic syndrome subtype refractory anemia with excess blasts; recent studies have raised the question if acute erythroleukemia should be considered as a myelodysplastic syndrome subtype. We reviewed 77 de novo acute erythroleukemia and 279 de novo refractory anemia with excess blasts from three large medical centers. Compared to refractory anemia with excess blasts, acute erythroleukemia patients had higher total bone marrow blasts, lower platelets, hemoglobin, and absolute neutrophil counts, with more patients being assigned a very-poor-karyotype risk and very-high Revised International Prognostic Scoring System score. Induction chemotherapy was administered to 55% of acute erythroleukemia patients, but was not associated with longer overall survival compared to acute erythroleukemia patients treated with lower-intensity therapies or supportive care (P = 0.44). In multivariable analysis of all patients, Revised International Prognostic Scoring System very high (P o0.0001) or high (P = 0.005) risk, but not a diagnosis of acute erythroleukemia (P = 0.30), were independent risk factors for shorter overall survival. Our data show that acute erythroleukemia patients have similar risk-adjusted outcome to refractory anemia with excess blasts patients and do not appear to gain survival advantage with acute myeloid leukemia-type induction chemotherapy. These data suggest that acute erythroleukemia, erythroid/myeloid subtype with o 20% blasts may be more appropriately classified as refractory anemia with excess blasts rather than as an acute myeloid leukemia subtype.

De novo pure erythroid leukemia: refining the clinicopathologic and cytogenetic characteristics of a rare entity

“…For myelodysplastic syndrome, several sentinel studies have shown that the determination of the myeloid blast count should be based on total bone marrow nucleated elements rather than as a fraction of the non-erythroid compartment because of the low reproducibility of non-erythroid blast counts and the close biological relationship between erythroleukemia and myelodysplastic syndrome. [1][2][3][4][5][6][7][8][9][10] In the previous 2001 and 2008 World Health Organization classifications, a second subtype of erythroleukemia (erythroid/myeloid type) was recognized in cases with 450% erythroid precursors of which ≥ 20% of the non-erythroid elements consisted of myeloid blasts. As has been shown by Wang and colleagues, it appears that the erythroid/myeloid type of erythroleukemia is biologically and clinically similar to erythroid-rich myelodysplastic syndrome and that small changes in the percent myeloid blasts can result in significant differences in the final diagnostic category.…”

“…[1][2][3] However, the former has been removed as a diagnostic category from the revised fourth edition World Health Organization classification because of the low reproducibility of non-erythroid blast counts and the close biological relationship between erythroleukemia and myelodysplastic syndrome based on findings from multiple, large comprehensive studies. [1][2][3][4][5][6][7][8][9][10][11] Pure erythroid leukemia is a rare and often challenging diagnosis. The diagnosis is typically difficult for several reasons, including morphologic similarity of pronormoblasts with other cell types, CD34 negativity in the erythroblasts, and weak to absent immunoreactivity for the erythroid-specific markers glycophorin A and hemoglobin.…”

Study of clinical, haematological and cytogenetic profile of patients with acute erythroid leukaemia

“…The latest amendment to the WHO classification in the year 2016 was a big stroke to the all the confusions surrounding this entity. The entity of AEL is being proposed to be removed [7–9]. The myeloblasts need to be counted as a percentage of the total marrow cells.…”

Myelodysplastic Syndrome Updated

“…The blast threshold for separating MDS from acute myeloid leukemia (AML) is now always 20%, with the exception of cases bearing the AML-defining cytogenetic abnormalities PML-RARA, inv (16) pathologic, and genetic features that are more akin to MDS than to AML [1,16]. Thus, stratification of myeloid neoplasms into entities lacking excess blasts, MDS with excess blasts-1, MDS with excess blasts-2, and AML is always based on myeloid blasts counted as a percentage of all nucleated marrow cells, irrespective of whether or not there is a prominent erythroid proliferation.…”