Lineage switch from T-cell lymphoblastic leukemia/lymphoma to acute myeloid leukemia and back to T-cell lymphoblastic leukemia/lymphoma in a patient diagnosed during pregnancy

Immune escape of B-cell lymphoblastic leukemic cells through a lineage switch to acute myeloid leukemia

Acute leukemia (AL) with a lineage switch (LS) is associated with poor prognosis. The predisposing factors of LS are unknown, apart from KMT2A rearrangements that have been reported to be associated with LS. Herein, we present two cases and review all 104 published cases to identify risk factors for LS. Most of the patients (75.5%) experienced a switch from the lymphoid phenotype to the myeloid phenotype. Eighteen patients (17.0%) experienced a transformation from acute myelogenous leukemia (AML) to acute lymphoblastic leukemia (ALL). Forty-nine (46.2%) patients carried a KMT2A rearrangement. Most of the cases involved LS from B-cell ALL (B-ALL) to AML (59.4%), and 49 patients (46.2%) carried KMT2A-rearrangements. Forty patients (37.7%) received lineage-specific immunotherapy. Our findings suggest that the prevalence of KMT2A rearrangements together with the lineage-specific immunotherapy may trigger LS, which supports the thesis of the existence of leukemia stem cells that are capable of lymphoid or myeloid differentiation.

Lineage switch from lymphoma to myeloid neoplasms: First case series from a single institution

Lymphoma relapse is very common in clinical work, but lineage switch at relapse is rare. Although some cases have reported acute lymphocytic leukemia (ALL) switch to acute myeloid leukemia (AML) or myeloid sarcoma upon relapse, phenotype switch seldom occurs in other types of lymphoma. Here we report six cases with lineage switch from lymphoma to myeloid neoplasms. In our cohort, three cases were mantle cell lymphoma (MCL), and the other three cases were T-cell lymphoblastic lymphoma (T-LBL), B-cell lymphoblastic lymphoma (B-LBL), and diffuse large B-cell lymphoma (DLBCL) at the initial diagnosis. When linage switch occurred, most cases were AML M5 phenotypes, and only one case was myelodysplastic syndrome (MDS) phenotype. 11q23/mixed-lineage leukemia (MLL) rearrangement was negative in all cases. Although intensive therapy and stem cell transplantation have been applied in most cases, the poor outcome cannot be reversed. Therefore, we found that lineage switch could occur not only from ALL to AML or vice versa, but also from MCL or DLBCL to AML. Moreover, the incidence of MLL rearrangement in lineage switch is lower in adult hematologic malignancies as compared with pediatric patients.

Lineage Plasticity in Cancer: The Tale of a Skin-Walker

Lineage plasticity, the switching of cells from one lineage to another, has been recognized as a cardinal property essential for embryonic development, tissue repair and homeostasis. However, such a highly regulated process goes awry when cancer cells exploit this inherent ability to their advantage, resulting in tumorigenesis, relapse, metastasis and therapy resistance. In this review, we summarize our current understanding on the role of lineage plasticity in tumor progression and therapeutic resistance in multiple cancers. Lineage plasticity can be triggered by treatment itself and is reported across various solid as well as liquid tumors. Here, we focus on the importance of lineage switching in tumor progression and therapeutic resistance of solid tumors such as the prostate, lung, hepatocellular and colorectal carcinoma and the myeloid and lymphoid lineage switch observed in leukemias. Besides this, we also discuss the role of epithelial-mesenchymal transition (EMT) in facilitating the lineage switch in biphasic cancers such as aggressive carcinosarcomas. We also discuss the mechanisms involved, current therapeutic approaches and challenges that lie ahead in taming the scourge of lineage plasticity in cancer.

Transformation from acute promyelocytic leukemia to acute myeloid leukemia with a CEBPA double mutation: A case report and review of the literature

INTRODUCTION

The transformation of acute promyelocytic leukemia (APL) to acute mononuclear leukemia during treatment is a rare clinical phenomenon, and no CCAAT/enhancer-binding protein alpha (CEBPA) double mutations have been reported.

PATIENT CONCERNS

A 42-year-old male was hospitalized for ecchymosis of the left lower limb for more than 1 month, gingival bleeding, and fatigue for 10 days, with aggravation of symptoms for 2 days.

DIAGNOSIS

A diagnosis of APL was based on bone marrow (BM) morphology, immunophenotyping, fusion gene analysis, and fluorescence in situ hybridization. At a 1-year follow-up of maintenance treatment, he developed thrombocytopenia and was diagnosed with acute myeloid leukemia (AML) with a CEBPA double mutation by BM morphology, immunotyping, chromosomal analysis, polymerase chain reaction, and next generation sequencing.

INTERVENTIONS

Complete remission of APL was achieved after all-trans retinoic acid and arsenic trioxide double induction therapy, followed by 2 cycles of mitoxantrone and cytarabine, and 1 cycle of idarubicin and cytarabine. Thereafter, sequential maintenance therapy of arsenic trioxide + all-trans retinoic acid + methotrexate was started. In the fourth cycle of maintenance therapy, APL was transformed into AML with a CEBPA double mutation. After 1 cycle of idarubicin and cytarabine, the patient achieved complete remission and received 3 cycles of idarubicin and cytarabine and three cycles of high-dose cytarabine as consolidation therapy.

OUTCOMES

At present, the patient is in continuous remission with minimal residual disease negative for both of APL and AML.

CONCLUSION

AML with a CEBPA double mutation after APL treatment is very rare, thus the prognosis of this event will require further observation.