[1330] CD141+ Myeloid Dendritic Cell Differentiation in Acute Myeloid Leukemia

Anna R Balog, Howard J Meyerson. University Hospitals Case Medical Center, Cleveland, OH

Background: Plasmacytoid dendritic cell proliferations are known to be associated with cases of chronic myelomonocytic leukemia. We hypothesized that myeloid dendritic cell differentiation may also be seen in association with leukemia. CD141, or thrombomodulin, is expressed on a subset of myeloid dendritic cells as well as endothelium. In this study, we investigated CD141 expression in acute myeloid leukemia and chronic myelomonocytic leukemia.
Design: CD141 expression was assessed by immunohistochemistry in a retrospective study of 53 cases of acute myeloid leukemia and five cases of chronic myelomonocytic leukemia from 2009 to 2012. The salient phenotypic and genetic features of cases with CD141+ staining were reviewed.
Results: Of the 53 acute myeloid leukemia cases evaluated, 42 cases were negative for CD141; five cases showed <5% positive cells; three cases approximately 5% positive cells; two cases approximately 10% positive cells; and one case showed variable staining, ranging from scattered positive cells to focal areas with 50% positive cells. Of the six cases with 5% or more CD141 staining, four were classified as acute monocytic leukemia, one as acute myelomonocytic leukemia, and one as acute myeloid leukemia with maturation. Of these six cases, cytogenetics revealed extra copies of chromosome 8 in three cases, including two cases of tetrasomy 8, a rare finding. CD141 evaluation of the five CMML cases showed three cases with rare positive cells. In all of the cases evaluated, CD141 highlighted endothelium and megakaryocytes.
Conclusions: Occasional cases of acute myeloid leukemia may show increased myeloid dendritic cells. Myeloid dendritic cell proliferation may be more common in acute myeloid leukemia with monocytic differentiation. A possible association between acute myeloid leukemia with evidence of myeloid dendritic cell differentiation and extra copies of chromosome 8 may exist.
Category: Hematopathology

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 232, Wednesday Morning

 

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