De novo lymphoid blastic phase chronic myeloid leukemia: report and contemporary discussion.

We herein describe two cases of de novo lymphoid blastic transformation in patients with no history of chronic-phase chronic myeloid leukemia (CP-CML), both of whom were labeled initially as Philadelphia positive B-Acute Lymphoblastic Leukemia (B-ALL). The first patient was an 18-year-old male who presented with subjective fever, intentional weight loss, generalized fatigue, and headache. Investigations showed leukocytosis (312 × 10^3/ul), thrombocytopenia and anemia. Flowcytometry was consistent with B-ALL, with aberrant expression of CD13 and CD33. He was found to be positive for De novo lymphoid blastic-phase CML can therefore be difficult to differentiate from Philadelphia positive B-ALL due to their overlapping clinical and laboratory picture, implying the need to do myeloid compartment evaluation at the time of diagnosis. With recent progress in the treatment of Philadelphia positive B-ALL, including the role of transplant with the use of novel agents, a better characterization of this disease entity in retrospective and prospective trials is warranted.