Chronic myelogenous leukemia (CML) is a clonal disorder starting with a chronic phase and progressing to an acute blastic phase. Philadelphia (Ph) chromosome formation results in the relocation of the ABL oncogene from the chromosome 9q34 to BCR region on 22qll, forming the BCR/ABL fusion gene. The Ph chromosome once detected rarely disappears, except as a result of therapy. We present an unusual Ph-positive CML case, which developed lymphoid blast crisis in complete cytogenetic remission following interferon-α and hydroxyurea therapy. Sequential cytogenetic investigations were carried out on bone marrow. After a standard Ph translocation seen at diagnosis, from the 8th month of therapy all metaphases showed a normal diploid karyotype. Fluorescence in situ hybridization detected residual BCR/ABL-positive inter-phase cells during the 12th month of therapy. In the 14th month, the patient showed 27% blasts in marrow though normal cytogenetics was maintained. Present findings suggest blastic transformation occurred in a Ph-negative lymphoid clone. This supports the hypothesis that an actual leukemogenic event occurs in a multipotent stem cell prior to the acquisition of Ph translocation.

This content is only available via PDF.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.