title: Biphenotypic leukemia with unusual chromosomal translocation in a patient treated for melanoma.
abstract: A patient in complete remission from malignant melanoma but with refractory anemia after nitrosourea treatment developed acute biphenotypic leukemia. This disease, progression was accompanied by expansion of a cytogenetically abnormal clone. At first cytogenetic analysis, 1 year post discontinuation of chemotherapy, only 25% of the metaphases examined were hypodiploid with monosomy 7. Six months later, all of the metaphases seen were 45,XY,-7. Six months before overt acute leukemia was diagnosed, an additional chromosome abnormality emerged, t(2;3)(q31;q27). Although the translocation was present in all metaphases examined, the patient progressed into an acute leukemia with two components: one TdT-positive, Ia-positive, and the other TdT-negative, Ia-positive, monocytoid antigen-positive. This mixed leukemia was identified by double fluorescence staining for intranuclear TdT and surface labeling with a monocyte-specific monoclonal antibody.
mesh_terms: D000208:Acute Disease; D000328:Adult; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis; D002900:Chromosomes, Human, 1-3; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007938:Leukemia / Q000139:chemically induced / Q000235:genetics* / Q000276:immunology; D008297:Male; D008545:Melanoma / Q000188:drug therapy*; D009378:Neoplasms, Multiple Primary; D015260:Neprilysin; D009607:Nitrosourea Compounds / Q000009:adverse effects*; D010641:Phenotype; D012673:Semustine / Q000009:adverse effects* / Q000627:therapeutic use; D014178:Translocation, Genetic
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D009607:Nitrosourea Compounds; D012673:Semustine; D015260:Neprilysin