Which disease is characterized by bone marrow making abnormal blood cells that do not mature properly?

• A. Leukemia
• B. Lymphoma
• C. Myelodysplastic syndromes (MDS)
• D. Anemia

Answer: (C)

Main concept: maturation defects in the bone marrow leading to ineffective hematopoiesis. In myelodysplastic syndromes, the marrow makes precursor blood cells that look abnormal and fail to mature into normal red cells, white cells, and platelets. Because these cells don’t mature properly, production is inefficient, causing low blood counts and related symptoms. This maturation defect and the resulting cytopenias are the hallmark of this condition, making it the best fit for the description. Leukemia centers on uncontrolled proliferation of malignant cells, often immature blasts, which is a different mechanism from maturation defects across lineages. Lymphoma is a cancer of lymphocytes primarily in lymph nodes, not defined by bone marrow maturation defects. Anemia describes low red blood cells as a consequence of many causes, but it doesn't specify abnormal maturation in the marrow. So the described pattern aligns with myelodysplastic syndromes.