p190 bcr-abl rearrangement: a secondary cytogenetic event in some chronic myeloid disorders?

Background and Objectives, A small number of chronic myeloproliferative dis orders with hematologic features of chronic myelomonocytic leukemia (CMML) or atypical chronic myeloid leukemia and Ph1 chromosome with m-BCR rearrang ement have been reported (p190 CMPD), We report here 3 new cases of p190 CM PD that had unusual features. In 2 of the cases the m-BCR rearrangement app eared to be a secondary event, Design and Methods, Patients were studied by cytogenetic, FISH, and molecul ar biology analyses and followed-up clinically, Results. The first patient initially had typical 5q-syndrome, without m-BCR rearrangement. Five years later, she developed hematologic features of CMM L, with t(9;22) translocation, m-BCR rearrangement and high levels of p190 BCR-ABL transcript. The second patient initially had hematologic characteri stics of chronic myeloid leukemia (CML) with t(9;22) translocation and m-BC R rearrangement but also other complex cytogenetic findings including 17p r earrangement, Monocytosis developed during the course of the disease. The t hird patient initially had agnogenic myeloid metaplasia (AMM), Five years l ater, while the hematologic characteristics were still those of AMM, a firs t karyotype showed a t(9;22) translocation and molecular analysis showed a very low level of p190 BCR-ABL transcript. Four years later, the patient de veloped hematologic features of atypical CML with blood monocytosis, t(9;22 ) and much greater (100 fold) p190 BCR-ABL transcript levels, Interpretation and Conclusions, Our 3 cases and review of the previously pu blished cases show the variability of clinical features of p190 positive CM PD, Our results also suggest that, at least in some cases, p190 BCR-ABL rea rrangement could be a secondary event in the course of a myeloid disorder, (C) 1999, Ferrata Storti Foundation.