The overall prognosis of non-Down syndrome pediatric acute megakaryoblastic leukemia (AMKL) is poor, although recent studies show heterogeneity in outcome depending on the defining genetic abnormality [1,2]. Some of these genetic aberrations are cryptic, and require fusion-specific reverse transcription polymerase chain reaction or whole transcriptome sequencing (WTS) for diagnosis [3].
In this case report, we give an in-depth account of the diagnosis and treatment of a
A 28–month-old girl first presented with easy bruising. The complete blood count (CBC) at the time showed white blood cell (WBC) count 6.65×109/L, hemoglobin 11.6 g/dL and platelet count of 16×109/L. Under the impression of immune thrombocytopenia, the patient was treated with intravenous immunoglobulin and predni-so-lone, but the thrombocytopenia persisted. Bone marrow (BM) examination done 2 months after the start of prednisolone showed 15% blasts, increasing to 24% blasts in a second BM study done with short-term follow-up. The CBC at the time of the second BM exam showed WBC 9.34×109/L, hemoglobin 10.0 g/dL and platelet 28×109/L, with no peripheral blasts. The BM blasts were positive for CD41a, CD33, CD38, CD4 and HLA-DR in immuno-phenotyping, while chromosome study showed a complex karyotype. Analysis of BM WTS data with the fusion detection tool Arriba [7] confirmed the presence of
The patient underwent remission induction chemotherapy with the combination of cytarabine 200 mg/m2/day for 7 days and daunorubicin 45 mg/m2/day for 3 days and 1 dose of intrathecal cytarabine. A follow-up BM study showed complete remission (CR), and the patient subsequently underwent second induction with high dose cytarabine and mitoxantrone, and consolidation with cytarabine and idarubicin. BM study done after second induction continued to show CR with minimal residual disease (MRD) negative status according to flow cytometry. Infectious toxicities were limited to one episode of
Due to the presence of a complex karyotype which designates a patient as high risk according to our acute myeloid leukemia (AML) treatment protocol, and the detection of the
Relevant findings from our patient include a young age at diagnosis of 32 months, the achievement of CR after the first course of remission induction chemotherapy despite the presence of a known poor prognosis
The optimum method of treating
An in-depth understanding of
With the emerging role of
Finally, although the initial report of
In summary, we describe in detail the diagnosis and treatment of a pediatric AMKL patient with
The authors have no conflict of interest to declare.