Undifferentiated leukemia of infancy with t(11:17) chromosomal rearrangement. Coexpressing myeloid and B cell restricted antigens.
It has been suggested that the malignant transformation, in some of the acute leukemias, may involve totipotent stem cells resulting in a biphenotypic leukemia expressing both myeloid, and lymphoid characteristics. We describe here a hybrid cell acute leukemia, in a 16-day-old infant, in whom leukemic cells coexpressed myeloid and lymphoid B cell antigens. Blast cells in the bone marrow showed L2 morphology according to the French American British (FAB) classification, with positive periodic-acid Schiff, and nonspecific esterase staining. Sudan black, and specific esterase were negative. Terminal deoxynucleotidyl transferase, was strongly positive in 5% of blasts, and faintly reactive with the rest. Karyotypic analysis demonstrated a translocation of t(11:17);(q23;p13). Immunoglobulin gene analysis revealed rearrangement of the heavy chain genes. The blasts' phenotype was HLA/DR+ B4+ My7+ My9+ common acute lymphoblastic leukemia antigen (CALLA) B1- T11-. Dual immunofluorescence staining using anti My7, and My9 fluorescein isothiocyanate, and anti B4 pycoerythrin conjugated monoclonal antibodies, and flow cytofluorometry, revealed a labeling pattern of 25% B4+; 10% to 15% My7+; 17% My9+; and 50% of cells coexpressing B4 My7, and My9 antigens. These results provide evidence for a hybrid leukemia with lymphomyeloblasts being part of a single clone, which may indicate the origin of this leukemic clone from a pluripotent (lymphoid/myeloid) stem cell.
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation; D002880:Chromosomes, Human, Pair 11; D002886:Chromosomes, Human, Pair 17; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000473:pathology; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007231:Infant, Newborn; D007938:Leukemia / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000276:immunology / Q000473:pathology; D011995:Recombination, Genetic; D014178:Translocation, Genetic
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D007143:Immunoglobulin Heavy Chains