PROGRESSION FROM MYELODYSPLASTIC SYNDROME TO ACUTE LYMPHOBLASTIC-LEUKEMIA WITH PHILADELPHIA-CHROMOSOME AND P190 BCR-ABL TRANSCRIPT

We describe a patient with Philadelphia chromosome (Ph(1))-positive ac ute lymphoblastic leukaemia (ALL) who developed it 2.5 years after bei ng diagnosed with myelodysplastic syndrome (MDS). The patient initiall y had refractory anaemia (RA), but progressed to refractory anaemia wi th excess blasts (RAEB) 2 years later, that terminated in ALL, An immu nophenotypic analysis of the lymphoblasts revealed CD10 and CD19 posit ive cells, The karyotype was normal 46,XY in RA phase, 46,XY,20q-durin g the RAEB phase, and 46,XY, t(9;22)(q34;q11), 20q-during the ALL phas e. Furthermore, p190 BCR-ABL mRNA was detected in the ALL blasts, Thes e findings indicate that this ALL arose from the MDS clone through mul tiple cytogenetic evolutions, the final event of which was the acquisi tion of p190 BCR-ABL type Ph(1).