title: Blasts-more than meets the eye: evaluation of post-induction day 21 bone marrow in CBFB rearranged acute leukemia.
abstract: Induction chemotherapy is often the first therapeutic intervention for acute myeloid leukemia (AML). Evaluation of post induction bone marrow provides critical information for clinical management; in general increased blast countsor increased marrow cellularity is an ominous sign, suggestive of ineffective therapy, and may warrant additional rounds of chemotherapy. However, increased blasts alone are not necessarily predictive of recurrent/persistent disease. Here we report a very unusual observation in a case of AML with a core binding factor beta (CBFB) rearrangement. In this case the day 21 post-induction marrow biopsy showed a high blast count (approximately 20%), however,subsequent fluorescence in-situ hybridization studies were negative for CBFB rearrangement. We compared this finding to post-induction marrows from a series of 6 AML cases with CBFB rearrangements, none of which showed an increased blast count. This case illustrates that increased blast counts, even those comprising 20% of cells, are not de facto evidence of induction failure, and that correlation with ancillary studies such as fluorescence in-situhybridization should be used to distinguish a persistent neoplastic clone, from a brisk marrow recovery.
authors.affiliation: Department of Pathology and Immunology, School of Medicine, Washington University in St. Louis St. Louis, MO, USA ; Department of Pathology, VA San Diego Healthcare System San Diego, CA, USA.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Pathology and Immunology, School of Medicine, Washington University in St. Louis St. Louis, MO, USA.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Duncavage
mesh_terms: D001854:Bone Marrow Cells / Q000187:drug effects / Q000473:pathology*; D050658:Core Binding Factor beta Subunit / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D060828:Induction Chemotherapy; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*; D008875:Middle Aged; D012074:Remission Induction
chemical_list: C493692:CBFB protein, human; D050658:Core Binding Factor beta Subunit
keywords: Core binding factor beta; DUP98; acute myeloid leukemia; day 21 marrow; inv(16); post induction; t(11;20)(p15;q11.2)