[Author affiliations not provided]
Background: Vitamin B12 deficiency is an important hematological disorder resulting from impaired DNA synthesis in rapidly dividing cells, leading to ineffective hematopoiesis and megaloblastic anemia. Although anemia is the most common manifestation, severe deficiency may occasionally present with pancytopenia, posing a diagnostic challenge. Early identification is essential because the condition is reversible with appropriate treatment.
Case Presentation: We report the case of a 55-year-old female with a known history of type 2 diabetes mellitus and hypertension who presented with complaints of giddiness for 20 days, palpitations and intermittent fever for two weeks, and cough with expectoration for one week. Clinical examination revealed pallor with stable vital parameters. Laboratory investigations demonstrated pancytopenia with severe anemia. Serial hematological evaluation showed hemoglobin levels ranging from 5.5–7.8 g/dL, platelet counts from 19,000–37,000/µL, and total leukocyte counts from 1,500–3,600/µL. Bone marrow aspiration and biopsy revealed normocellular marrow with marked erythroid hyperplasia, megaloblastic maturation, binucleated erythroid precursors, and altered myeloid-to-erythroid ratio, consistent with ineffective hematopoiesis due to nutritional deficiency. No dysplastic cells, blasts, or marrow fibrosis were identified. These findings supported the diagnosis of vitamin B12 deficiency–associated megaloblastic anemia presenting as pancytopenia. The patient showed gradual hematological improvement on follow-up evaluation.
Conclusion: Vitamin B12 deficiency should be considered in the differential diagnosis of unexplained pancytopenia. Bone marrow examination plays a crucial role in identifying characteristic megaloblastic changes and excluding other hematological disorders. Early recognition and timely treatment can lead to significant hematological recovery and prevent potential complications.
MeSH Keywords: Vitamin B12 Deficiency; Pancytopenia; Megaloblastic Anemia; Bone Marrow Examination; Erythroid Hyperplasia; Diabetes Mellitus, Type 2; Hematologic Diseases.
How to cite this article: [Author Names]. Vitamin B12 Deficiency Presenting as Pancytopenia with Megaloblastic Bone Marrow Changes in a Patient with Type 2 Diabetes Mellitus: A Case Report. Int J Drug Deliv Technol. 2026;16(6s): 522-528; DOI: 10.25258/ijddt.16.6s.77
Source of support: None
Conflict of interest: None