Rapid transformation of atypical myeloproliferative disorder with consistent t(8;13) to B-cell acute lymphoblastic leukemia: a case report.

8p11 myeloproliferative syndrome (EMS; also known as the stem cell leukemia syndrome-SCLL) is a rare atypical myeloproliferative disorder associated with chromosomal abnormalities involving the 8p11 chromosomal band. Translocations associated with this syndrome result in the fusion of the fibroblast growth factor receptor 1 (FGFR 1) gene with various partners, resulting in ligand independent FGFR activity. The most commonly observed translocation of this syndrome is t(8;13), which results in the expression of a chimeric ZNF198-FGFR1 tyrosine kinase. Disease phenotype associated with this translocation has some typical features such as poor prognosis, and transformation to mainly acute leukemia and non-Hodgkin lymphoma; commonly with a T-cell phenotype in which obtaining and maintenance of remission is difficult by conventional chemotherapy. We hereby present a case diagnosed as atypical chronic myeloproliferative disease with consistent t(8;13)(p12;q12) and transformed rapidly to pre-B-cell acute lymphoblastic leukemia which is a rare clinical presentation.