Development of Myelodysplastic Syndrome in a Patient With Pernicious Anemia During the Course of Replacement Treatment.

Megaloblastic anemia (MBA) is a reversible metabolic disorder that responds well to vitamin B12 supplementation. It contrasts with myelodysplastic syndrome (MDS), an irreversible neoplastic condition characterized by hematopoietic stem cell abnormalities. To date, no association has been identified between these two distinct etiologies, and they are considered independent diseases. However, despite their distinct classifications, both conditions present macrocytic anemia, similar bone marrow findings, and sometimes have common chromosomal abnormalities, which can lead to occasional misdiagnoses. Herein, we present a patient initially diagnosed with pernicious anemia (PA) who showed improvement with replacement therapy but subsequently became resistant to treatment and eventually developed MDS. Quantitative assessment of Wilm's tumor-1 (WT1) mRNA has emerged as a valuable tool for gauging MDS disease status and distinguishing it from related disorders, such as aplastic anemia. In our investigation of 30 patients with MBA, we explored WT1 mRNA expression. We observed its presence in 10 patients with PA, which suggests a potential link between PA and hematopoietic tumors.