A case of BCR::ABL1-positive B-cell acute lymphoblastic leukemia (B-ALL) initially mimicked acute promyelocytic leukemia (APL) due to blast cells with abundant azurophilic granules. However, the diagnosis was corrected by negative myeloperoxidase (MPO) staining, a B-cell immunophenotype, and genetic studies. This highlights the importance of integrated diagnostics in differentiating granular B-ALL from APL.