title: Acute biphenotypic leukaemia (myeloid and null-ALL type) supervening in a myelodysplastic syndrome.
abstract: An acute leukaemia was seen in a 72-year-old patient with a myelodysplastic syndrome (MDS) of 14 months duration, who had been treated only with steroids. The morphological appearance of the blast cells suggested a poorly differentiated cell type. Surface marker analysis, including double staining studies, showed the coexistence of a population of null acute lymphoblastic leukaemia (ALL) blast cells together with acute myeloid leukaemia type cells. No chromosomal alterations were detected. The change from a chronic MDS to an acute leukaemia of mixed (myeloid and null ALL) type suggests either transformation of a pre-existing abnormal clone or de novo appearance of two separate leukaemic clones.
mesh_terms: D000368:Aged; D001853:Bone Marrow / Q000473:pathology; D006412:Hematopoietic Stem Cells / Q000473:pathology; D006801:Humans; D007945:Leukemia, Lymphoid / Q000209:etiology* / Q000473:pathology; D015470:Leukemia, Myeloid, Acute / Q000209:etiology* / Q000473:pathology; D008215:Lymphocytes, Null; D008297:Male; D009190:Myelodysplastic Syndromes / Q000150:complications* / Q000473:pathology; D010641:Phenotype