Blast crisis

Blast phase of chronic myelogenous leukemia (CML), which can be discovered incidentally on CBC or in assessment of patients with symptoms and signs such as fever, fatigue, weight loss, anemia, thrombocytopenia, or splenomegaly.

Diagnosis of CML requires presence of a Philadelphia chromosome gene mutation. Diagnosis of the blast phase of CML is based on percentage of blasts in peripheral smear or bone marrow.

Tyrosine kinase inhibitors are paramount in treatment. Allogeneic stem cell transplant must follow due to rapid relapse.

Blast crisis refers to the transformation of chronic myelogenous leukemia (CML) from the chronic or accelerated phase to blast phase. This is characterized by blast cells (≥20% by WHO criteria; ≥30% by MD Anderson Cancer Center and the International Bone Marrow Transplant Registry criteria) in the peripheral blood smear or the bone marrow, or the presence of an extramedullary accumulation of blast cells, or large foci or clusters of blasts in the bone marrow biopsy.[1]Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016 May 19;127(20):2391-405. [Erratum in: Blood. 2016 Jul 21;128(3):462.] http://www.bloodjournal.org/content/127/20/2391.long http://www.ncbi.nlm.nih.gov/pubmed/27069254?tool=bestpractice.com [2]National Comprehensive Cancer Network. Chronic myeloid leukemia. 2018 [internet publication]. https://www.nccn.org/professionals/physician_gls/default.aspx CML is characterized by the presence of the Philadelphia chromosome, which results from a reciprocal translocation of chromosomes 9 and 22, juxtaposing the proto-oncogene c-abl from chromosome 9 to the breakpoint cluster region in chromosome 22.[3]Ghelani D, Sneed TB, Bueso-Ramos CE, et al. Chapter 4. Chronic myeloid leukemia. In: Kantarjian HM, Wolff RA, Koller CA, eds. MD Anderson manual of medical oncology. New York, NY: McGraw-Hill; 2006:57-74.