Clinical Characteristics and Treatment Outcome of Childhood Acute Lymphoblastic Leukemia With the t ( 4 ; l l ) ( q 21 ; q 23 ) : A Collaborative Study of 40 Cases
The t(4;11)(q21;q23) chromosomal abnormality was identified in 40 (2%) of 1,986 children with newly diagnosed acute lymphoblastic leukemia (ALL). This translocation was associated with female sex (63%). age less than 1 year (60%). hyperleukocytosis (median leukocyte count, 156.5 x 109/L), CDlO-/CD19+ B-precursor cell immunophenotype, and myeloid-associated antigen (CD15) expression (63%). Nearly all cases had at least some CD24blast cells. The CDlO-/CD15+/ CDl9'/CD24-'+ phenotype was found in 20 of the 32 t(4;ll) cases tested. None of the 40 cases had the cytogenetic finding of hyperdiploidy >50, which is a favorable prognostic feature. For clinical comparison, the t(4; 11) cases were