Diagnostic ambiguity in BCR-ABL1–positive MPAL in a resource-limited setting: A case report

Diagnostic ambiguity in BCR-ABL1–positive MPAL in a resource-limited setting: A case reportKey Clinical Message:Mixed phenotype acute leukemia (MPAL) is a rare hematologic malignancy with significant diagnostic and therapeutic challenges.This case of BCR-ABL1–positive MPAL, diagnosed through integrated morphologic, immunophenotypic, and cytogenetic evaluation, emphasizes the need for heightened awareness of high-risk acute leukemias with significant therapeutic implications, particularly in resource-limited settings.AbstractMixed phenotype acute leukemia (MPAL) is a rare hematologic malignancy characterized by the presence of both myeloid and lymphoid lineage markers, posing significant diagnostic and therapeutic challenges. The presence of BCR-ABL1 further complicates classification and management, as it carries important prognostic and therapeutic implications.We report a case of BCR-ABL1–positive MPAL diagnosed through integrated morphologic, immunophenotypic, and cytogenetic evaluation. The case highlights key diagnostic pitfalls and underscores the importance of comprehensive immunophenotyping and molecular testing to avoid misclassification as acute myeloid leukemia or acute lymphoblastic leukemia. Recognition of this entity is critical for appropriate therapeutic decision-making, including the use of tyrosine kinase inhibitors. This report emphasizes the need for heightened awareness of MPAL with BCR-ABL1, representing a form of high-risk acute leukemia with significant therapeutic implications, particularly in resource-limited settings where diagnostic constraints may delay optimal management.Keywords: Mixed phenotype, leukemia, BCR-ABL1, tyrosine kinase inhibitors, diagnostic challenge