Myelodysplastic SyndromeAcute Myeloid Leukemia Arising in Idiopathic Erythrocytosis

Abstract EN

The term “idiopathic erythrocytosis (IE)” is applied to those cases where a causal clinical or pathological event cannot be elucidated and likely reflects a spectrum of underlying medical and molecular abnormalities.

The clinical course of a patient with IE is described manifesting as a persistent erythrocytosis with a low serum erythropoietin level, mild eosinophilia, and with evidence of a thrombotic event.

The patient subsequently developed a myelodysplasic syndrome (MDS) and acute myeloid leukemia (AML), an event not observed in erythrocytosis patients other than those with polycythemia vera (PV).

Application of a next-generation sequencing (NGS) approach targeted for myeloid malignancies confirmed wild-type JAK2 exons 12–15 and identified a common SH2B3 W262R single-nucleotide polymorphism associated with the development of hematological features of myeloproliferative neoplasms (MPNs).

Further NGS analysis detected a CBL L380P mutated clone expanding in parallel with the development of MDS and subsequent AML.

Despite the absence of JAK2, MPL exon 10, or CALR exon 9 mutations, a similarity with the disease course of PV/MPN was evident.

A clonal link between the erythrocytosis and AML could be neither confirmed nor excluded.

Future molecular identification of the mechanisms underlying IE is likely to provide a more refined therapeutic approach.