What are the manifestations of hyperplastic anemia in bone marrow findings?

In general, the bone marrow findings in hyperplastic anemia have typical characteristics, mainly including active bone marrow proliferation, marked erythroid hyperplasia, decreased myeloid-to-erythroid ratio, morphological abnormalities in erythroid cells, and normal or increased megakaryocytes and platelets. The specific analysis is as follows:

1. Active bone marrow proliferation: Bone marrow aspiration reveals markedly active marrow proliferation with increased numbers of hematopoietic cells, especially those involved in red blood cell production. This reflects the body's compensatory response to peripheral red blood cell deficiency through enhanced hematopoietic activity.

2. Marked erythroid hyperplasia: There is an increase in all stages of erythroid precursors—proerythroblasts, basophilic erythroblasts, polychromatophilic erythroblasts, and orthochromatic erythroblasts—with predominant proliferation of polychromatophilic and orthochromatic erythroblasts. These cells are densely arranged, indicating accelerated red blood cell production in the bone marrow.

3. Decreased myeloid-to-erythroid ratio: Normally, the ratio of granulocytes to erythrocytes in the bone marrow is approximately 2–4:1. In hyperplastic anemia, due to significant erythroid hyperplasia and relatively stable or slightly reduced granulocyte counts, this ratio is markedly decreased.

4. Morphological abnormalities in erythroid cells: Different types of hyperplastic anemia are associated with specific morphological changes in erythroid cells. For example, in iron-deficiency anemia, polychromatophilic and orthochromatic erythroblasts are smaller in size, have scant cytoplasm with a bluish staining tendency, and exhibit dense nuclear chromatin.

5. Normal or increased megakaryocytes and platelets: Megakaryocyte counts in the bone marrow are usually within the normal range. In some patients, due to compensatory mechanisms, megakaryocyte numbers may be mildly increased. Platelet production is not significantly affected, so platelet counts remain normal or slightly elevated—this contrasts sharply with the abnormal erythroid hyperplasia.

In clinical practice, the specific type of hyperplastic anemia should be determined by integrating bone marrow findings with peripheral blood tests and patient history. Once the underlying cause is identified, targeted treatment can be initiated. During treatment, regular follow-up bone marrow examinations and complete blood counts are necessary to monitor recovery of hematopoietic function and guide adjustments in therapy.