In the 2016 revision of the World Health Organization classification the term therapy-related myeloid neoplasia (t-MN) defines a subgroup of acute myeloid leukemia (AML) comprising patients who develop myelodysplastic syndrome (MDS-t) or acute myeloid leukemia (AML-t) after treatment with cytotoxic and/or radiation therapy for various malignancies or autoimmune disorders. We report the case of a 36 year old patient with t-MN (t-MDS) after achieving complete remission (CR) of a PML-RARA positive acute promyelocytic leukemia (APL) at 32 months after diagnosis. Initially classified as low risk APL and treated according to the AIDA protocol - induction and 3 consolidation cycles - the patient achieved a complete molecular response in September 2013 and started maintenance therapy. On follow-up PML-RARA transcript remained negative. In January 2016 leukopenia and thrombocytopenia developed and a peripheral blood smear revealed hypogranular and agranular neutrophils. Immunophenotyping in the bone marrow aspirate identified undifferentiated blast cells that did not express cytoplasmic myeloperoxidase. The cytogenetic study showed normal karyotype. The molecular biology tests not identified PMLRARA transcript. A diagnosis of t-MDS (AREB-2 - WHO 2008) was established. Treatment of AML was started with 2 “3+7” regimens and 1 MEC cycle. Two months from diagnosis, while in CR, an allogeneic HSCT from an unrelated HLA compatible donor was performed after myeloablative regimen. An unfavorable clinical evolution was followed by death on day 9 after transplantation. The occurrence of t-MNs during CR of APL represents a particular problem in terms of follow-up and differential diagnosis of relapse and constitutes a dramatic complication for a disease with a favorable prognosis.
This work was supported by the grants PN 41-087 /PN2-099 from the Romanian Ministry of Research and Technology