title: In vivo clonal evolution of pre-B to B-cell acute lymphoblastic leukemia in childhood.
abstract: Two cases are described that provide further evidence for clonal evolution in pre-B-cell acute lymphoblastic leukemia. Two infants, whose lymphoblasts at diagnosis were morphologically subtyped as L1 and immunophenotyped as HLA DR+, CD19+, CD10+/- and C mu-, were induced and maintained in remission. One child relapsed 6 months after initiation of therapy. This time his lymphoblasts had L3 morphology and immunophenotyping demonstrated the appearance of surface immunoglobulins. The second child relapsed 18 months after initiation of therapy with a lymphomatous picture. He also had peripheral and bone marrow blasts with L3 morphology and surface immunoglobulins. A lymph node biopsy showed diffuse small non-cleaved lymphoma with a 'starry sky' appearance compatible with Burkitt's lymphoma. Only one case with a similar clonal evolution has been reported in the literature, but no surface immunoglobulins were demonstrated. The significance of clonal evolution in these cases and its potential practical implications are discussed.
authors.affiliation: Institute of Hematology, Chaim Sheba Medical Center, Tel-Hashomer, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Toren
authors.forename: G
authors.initials: G
authors.lastname: Kende
authors.forename: M
authors.initials: M
authors.lastname: Mandel
authors.forename: M
authors.initials: M
authors.lastname: Biniaminov
authors.forename: F
authors.initials: F
authors.lastname: Brok-Simoni
authors.forename: E
authors.initials: E
authors.lastname: Rosenthal
authors.forename: I
authors.initials: I
authors.lastname: Engelberg
authors.forename: Y
authors.initials: Y
authors.lastname: Neumann
authors.forename: G
authors.initials: G
authors.lastname: Kenet
authors.forename: I
authors.initials: I
authors.lastname: Ben-Bassat
mesh_terms: D002999:Clone Cells; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D008297:Male; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*