B Lineage Acute Lymphoblastic Leukemia with concurrent IGH and EPOR rearrangements – An Entity with Dismal Outcome

The EPOR rearrangement, an uncommon cytogenetic abnormality linked to BCR::ABL1-like B-ALL, is often underdiagnosed due to the absence of a robust testing strategy, especially in resource-constrained settings. We report six cases of B-ALL with concurrent IGH and EPOR rearrangement from India, representing 1.3% of the tested cases, and reviewed the existing literature. The age ranged from 13 to 37 years (median 17 years), with a 2:1 male dominance. Leukocytosis was observed in 67% of patients (median total leukocyte count-105.9 × 10^9/L), and CD20 expression was seen in 67%. One patient experienced induction failure, while three relapsed within a year of diagnosis and treatment. All six patients died within 6 to 21 months of follow-up. These findings align with previous reports of treatment resistance, frequent relapses, and the need for novel therapeutic agents like JAK inhibitors and CART therapy. In summary, these six B-ALL cases with IGH and EPOR rearrangements highlight the diagnostic challenges and poor outcomes associated with this condition.