A Myelodysplastic Syndrome Patient with Del(9Q) Cytogenetic Aberration: A Rare Case Report

Abstract: Deletion of the long arm of chromosome 9 [del(9q)] is an exceptionally rare cytogenetic abnormality in myelodysplastic syndrome (MDS), more frequently described in acute myeloid leukemia. Due to the paucity of reported cases, the clinical behavior and optimal management of del(9q) MDS remain poorly defined. A 51-year-old Indonesian woman presented with transfusion-dependent anemia and thrombocytopenia. Bone marrow evaluation revealed dysplastic features consistent with MDS, and cytogenetic analysis demonstrated an isolated deletion of 9q [del(9)(q33–qter)]. The patient was treated with lenalidomide 10 mg daily on days 1–21 of a 28-day cycle. The treatment was well tolerated without major adverse effects or cytopenic complications during more than four years of follow-up. A sustained hematologic improvement was observed, characterized by progressive normalization of hemoglobin levels, stable leukocyte counts, and recovery of platelet counts. The patient achieved complete transfusion independence within several months and maintained clinical stability throughout the observation period. This case highlights the potential efficacy and tolerability of lenalidomide in MDS with isolated del(9q), suggesting that its therapeutic benefits may extend beyond the del(5q) subset.