Erythroblastic transformation of chronic myeloid leukemia: hyperdiploid Ph1-positive karyotypes in primitive PAS-positive erythroblasts.

In a case of erythroblastic transformation of chronic myeloid leukemia, morphological, cytochemical, and cytogenetic properties of marrow cells were studied on three occasions. It was investigated whether any correlation could be demonstrated between these cytological parameters. The following observations suggested that early erythroblasts with granular periodic acid-Schiff (PAS) positivity had hyperdiploid Ph1-positive karyotypes: (1) At the three times of study, the frequencies of Ph1-positive, hyperdiploid karyotypes varied in phase with the frequencies of erythroblast mitoses and inversely to those of granulopoietic mitoses. (2) In the three consecutive bone marrow samples, the frequencies of early erythroblasts (E1 + E2) presenting granular PAS positivity corresponded to and showed a statistically significant positive correlation to those of Ph1-positive hyperdiploid metaphases.