title: Acute lymphoblastic leukemia at relapse in a child with acute myeloblastic leukemia.
abstract: We describe a child diagnosed as having acute myelogenous leukemia (AML) at 25 months of age who relapsed with acute lymphoblastic leukemia (ALL) 1 year later. The AML was morphologically M2 by the French-American-British classification, periodic acid Schiff (PAS) stain negative and peroxidase positive. The ALL was L1 by this classification, PAS positive, and peroxidase negative. The initial AML was associated with a small segment deletion of the long arm of chromosome 11 [46, XY, de (11) (q23)] not seen in the relapse ALL, which had a normal karyotype. The child was rapidly reinduced with vincristine and prednisone, and remains in remission on maintenance lymphoma type (LSA2-L2) therapy more than 2 years later. These findings suggest the development of a new leukemic clone, rather than a phenotypic modulation of the initial leukemia.
authors.forename: M L
authors.initials: ML
authors.lastname: Bernstein
authors.forename: D W
authors.initials: DW
authors.lastname: Esseltine
authors.forename: J
authors.initials: J
authors.lastname: Emond
authors.forename: M
authors.initials: M
authors.lastname: Vekemans
mesh_terms: D001853:Bone Marrow / Q000473:pathology; D002675:Child, Preschool; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002906:Chromosomes, Human, 6-12 and X; D006801:Humans; D007621:Karyotyping; D007945:Leukemia, Lymphoid / Q000150:complications* / Q000235:genetics / Q000473:pathology; D015470:Leukemia, Myeloid, Acute / Q000150:complications* / Q000235:genetics / Q000473:pathology; D008297:Male