Chronic myeloid leukemia presenting in lymphoblastic crisis, a differential diagnosis with Philadelphia-positive B-lymphoblastic leukemia
Zhining Chen, Shimin Hu, Sa A. Wang, Marina Konopleva, Zhenya Tang, Jie Xu, Shaoying Li, Gökçe Törüner, Beenu Thakral, L. Jeffrey Medeiros, Guilin Tang
Abstract
Rare patients with chronic myeloid leukemia (CML) can present initially in lymphoblastic crisis (LBC) mimicking Ph + B-lymphoblastic leukemia (B-ALL). We retrospectively reviewed 275 adults who diagnosed initially as Ph + B-ALL and identified 28 patients with at least one of three features supporting the diagnosis of CML-LBC: 1) a large discrepancy between the blast count and Ph + clone; 2) Ph + clone persistent when B-ALL in remission; 3) BCR/ABL1 fusion detected in segmented cells. BCR-ABL1 fusions were p210 in 25 patients and p190 in 3 patients. In comparison to patients with Ph + B-ALL, patients with CML-LBC were older; had higher leukocyte and absolute neutrophil counts; higher immature myeloid cells in peripheral blood; lower blast counts; and inferior outcomes. In addition, we prospectively analyzed 26 patients with Ph + B-lymphoblastic leukemia and identified 8 patients with features more consistent with CML-LBC. These findings highlight the importance of distinguishing CML-LBC from de novo Ph + B-ALL.