THE DYNAMIC OF MDS DIAGNOSIS: FROM MULTI-LINEAGE DYSPLASIA AND HIGH BLASTS TO LMMC - A CASE REPORT

Abstract

Introduction: Myelodysplastic neoplasms (MDS) is a heterogeneous group of hematologic diseases characterized by cytopenias in one or more hematologic lineages and multiple dysplasias. Myeloproliferative neoplasms (MPN) are characterized by an increase in production of differentiated hematopoietic cells. MDS/MPN overlap syndromes diagnoses have different clinical manifestations and the most common of them is chronic myelomonocytic leukemia (CMML) which is defined by an abnormal production of monocytic cells and an increase of risk to secondary acute myeloid leukemia (AML) progression. According to the 2016 World Health Organization (WHO) classification, CMML, listed amongst the MDS/MPN overlap disorders, is divided into CMML-0 (cases with 2% blasts in the blood and 5% blasts in the bone marrow), CMML-1 (2 to 4% blasts in the blood and/or 5 to 9% blasts in the bone marrow), and CMML-2 (5 to 19% blasts in the blood and 10 to 19% blasts in the bone marrow). This report aims to exhibit the importance of follow-up patients to detect progression from MDS with a high percentage of blasts to CMML. Case report: A 73-year-old woman with asymptomatic pancytopenia was submitted to our care in 2018. The bone marrow aspiration and immunohistochemical exam showed multilineage dysplasia, 4% of blasts and the bone biopsy presented 85% cellularity. Also, the monocytic count was 1115/mm3. The karyotype was normal in 20 metaphases. In 2019, the patient appeared with ecchymosis and new exams showed bicytopenia, 6% of blasts with 85% cellularity and the monocytic count was less than 1800/mm3. In 2020, she was diagnosed with MDS with an IPSS-R score of 3.5, bicytopenia and the monocytic count was less than 1400. But, in 2021, the monocytic count rose to 6100/mm3. It was then that her clinical condition evolved to a CMML-1. She was 76 years old when it was decided that she be treated with hydroxyurea. The first response wasn't as expected, so the medication was replaced to azacitidine in the middle of 2022. The second response to treatment was very well documented, however, the treatment with azacitidine suffered several interruptions due to lack of medicine which led the monocyte count to rise. Discussion: Patients with MDS who showed relative monocytosis (≥10% in peripheral blood) and an increase of absolute count of monocytes (≥ 1 × 10̂9/L) are related to a high risk of progression to CMML with a positive predictive value (PPV) of 71,4%. The follow-up and the correct diagnosis is essential in MDS/MPN overlap syndromes since their prognosis and clinical implications differ from these isolated disorders. The patient in question started to be followed up in 2018 where multiple exams were made to discard other diseases, but the monocyte count was always carefully observed due to the risk of progression to CMML, which was detected in 2021. Then, the treatment was required. The use of hypomethylating agents can be considered for CMML patients if excess blasts or poor prognosis factors are present. The azacitidine was used and was able to revert to a normal monocyte profile with improved hemoglobin count, although the interruption of treatment because of lack of medicine in Unified Health System (SUS) demonstrates a treatment failure. Conclusion: Monitoring the progress of MDS in the patient was able to detect CMML at the beginning and already start the treatment.