Progression from myelodysplastic syndrome to acute lymphoblastic leukaemia with Philadelphia chromosome and p190 BCR-ABL transcript.

We describe a patient with Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukaemia (ALL) who developed it 2.5 years after being diagnosed with myelodysplastic syndrome (MDS). The patient initially had refractory anaemia (RA), but progressed to refractory anaemia with excess blasts (RAEB) 2 years later, that terminated in ALL. An immunophenotypic analysis of the lymphoblasts revealed CD10 and CD19 positive cells. The karyotype was normal 46,XY in RA phase, 46,XY,20q-during the RAEB phase, and 46,XY,t(9;22)(q34;q11),20q-during the ALL phase. Furthermore, p190 BCR-ABL mRNA was detected in the ALL blasts. These findings indicate that this ALL arose from the MDS clone through multiple cytogenetic evolutions, the final event of which was the acquisition of p190 BCR-ABL type Ph1.