Myelodysplastic Neoplasm with Increased Blasts-1 Presenting with Concurrent Diagnostic and Prognostically Relevant Morphologic Features: A Case Report.

INTRODUCTION: Myelodysplastic neoplasms (MDS) are clonal hematopoietic disorders characterized by ineffective hematopoiesis, cytopenias, and morphologic dysplasia, with a variable risk of progression to acute myeloid leukemia. Despite advances in molecular diagnostics, bone marrow morphology remains a cornerstone of diagnosis and risk stratification. CASE PRESENTATION: We report the case of a 72-year-old woman who presented with progressive fatigue and pancytopenia. Bone marrow examination revealed prominent dyserythropoiesis, dysgranulopoiesis, numerous micromegakaryocytes with unilobed nuclei, scattered atypical spindle-shaped mast cells, and 5-7% blasts. These findings fulfilled the diagnostic criteria for myelodysplastic neoplasm with increased blasts-1 (MDS-IB1) according to the WHO 2022 classification. Conventional cytogenetics demonstrated a normal female karyotype. CONCLUSION: This case illustrates the diagnostic and prognostically relevant value of concurrent morphologic abnormalities across multiple hematopoietic lineages in MDS. It underscores the enduring importance of meticulous bone marrow morphologic assessment, particularly when comprehensive molecular data are not immediately available.