Hyperdiploidy of 54 chromosomes with double Ph1 chromosome in lymphoid chronic myelocytic leukemic blast crisis.

Cytogenetic analysis of bone marrow cells in a 40-year-old man revealed a mosaic of two cell lines during blast crisis: one diploid with typical Ph1 chromosome (46 XY Ph1) and one with hyperdiploidy of 54 chromosomes with double Ph1 chromosome, trisomy 4, 6, 8, 18, 21 and duplication of the sex chromosomes X and Y. Immunological characterization showed common acute lymphoblastic leukemia antigen in 90% of the blasts. In spite of intensive chemotherapy the patient died in a third blast crisis 15 months after the first blast crisis, 3 months after successfully treated central nervous system relapse.