title: B-Lymphoblastic Leukemia in Patients With Chronic Lymphocytic Leukemia: A Report of Four Cases.
abstract: OBJECTIVE
  B-lymphoblastic leukemia (B-LBL) arising in patients with chronic lymphocytic leukemia (CLL) is exceedingly rare and poorly characterized.
  
  
  METHODS
  We describe four patients with CLL and concurrent or subsequent B-LBL diagnosed by morphologic, immunophenotypic, cytogenetic, and molecular analysis and reviewed the literature.
  
  
  RESULTS
  In three patients, B-LBL followed CLL by 5 to 15 years, and in one patient, B-LBL was diagnosed simultaneously with CLL. In all cases, the CLL had a typical immunophenotype, and the B-LBL blasts showed an immature B-cell immunophenotype with expression of CD10, CD19, and TdT and absence of surface immunoglobulin. In two patients, B-LBL blasts harbored t(9;22)(q34;q11.2)/BCR-ABL1. We sequenced the IGHV genes in both CLL and B-LBL in two patients and showed that IGHV usage differed.
  
  
  CONCLUSIONS
  Our data suggest that at least some cases of B-LBL arising in patients with CLL are independent, secondary neoplasms rather than a manifestation of histologic transformation.
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Zaher
authors.initials: Z
authors.lastname: Chakhachiro
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: C Cameron
authors.initials: CC
authors.lastname: Yin
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Lynne V
authors.initials: LV
authors.lastname: Abruzzo
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Tariq N
authors.initials: TN
authors.lastname: Aladily
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Lynn L
authors.initials: LL
authors.lastname: Barron
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Haley E
authors.initials: HE
authors.lastname: Banks
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Thomas
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: Michael
authors.initials: M
authors.lastname: Keating
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston.
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.affiliation: From the Departments of Hematopathology and LeukemiaUniversity of Texas MD Anderson Cancer Center, Houston. yhuh@mdnaderson.org.
authors.forename: Yang O
authors.initials: YO
authors.lastname: Huh
mesh_terms: D000369:Aged, 80 and over; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000473:pathology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
keywords: B-lymphoblastic leukemia; BCR-ABL1; Chronic lymphocytic leukemia; Philadelphia chromosome; t(9;22); transformation