title: B-cell acute lymphoblastic leukemia with t(4;11)(q21;q23) in a young woman: evolution into mixed phenotype acute leukemia with additional chromosomal aberrations in the course of therapy.
abstract: About 5% of adult B-cell acute lymphoblastic leukemias (B-ALL) are characterized by t(4;11)(q21;q23), which confers peculiar features to this B-ALL subtype, including a very immature immunophenotype and poor prognosis. We describe the case of a 21-year-old female who presented with B-ALL carrying the t(4;11)(q21;q23) and blasts positive for CD19, TdT, CD79a, CD38, HLA-DR. Before completing the Hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) therapy regimen, the B-cell leukemic clone still was detected, but an additional leukemic clone appeared, with morphology and immunophenotype (CD13, CD33, CD64, CD38, CD56, CD15, CD4(dim)) compatible with derivation from the myeloid/monocytic lineage. Karyotype showed the co-existence of three cell lines, with persistence of t(4;11)(q21;q23) and appearance of +8,+12,+13 and two der(4). The patient died because of disseminated intravascular coagulation. Our report describes a rare, possible evolution of such a subtype of B-ALL, with transformation into mixed phenotype acute leukemia in the course of therapy. This finding suggests a blast cell derivation from a common lymphoid/monocytic precursor leading to a final bilineal acute leukemia.
authors.affiliation: Division of Hematology, Department of Clinical and Experimental Medicine, University of Pisa;
authors.forename: Giovanni
authors.initials: G
authors.lastname: Carulli
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marini
authors.forename: Maria I
authors.initials: MI
authors.lastname: Ferreri
authors.forename: Antonio
authors.initials: A
authors.lastname: Azzarà
authors.forename: Virginia
authors.initials: V
authors.lastname: Ottaviano
authors.forename: Tiziana
authors.initials: T
authors.lastname: Lari
authors.forename: Melania
authors.initials: M
authors.lastname: Rocco
authors.forename: Stefano
authors.initials: S
authors.lastname: Giuntini
authors.forename: Mario
authors.initials: M
authors.lastname: Petrini
keywords: MLL gene; acute lymphoblastic leukemia; acute myeloid leukemia; mixed phenotype acute leukemia; t(4;11)(q21;q23).