SHM Converge Scientific Abstract ePoster Gallery-To B or Not to B: Vitamin B12 Deficiency or Aml?

Pdf Summary

This case describes a 73-year-old man with Crohn’s disease who presented with exertional shortness of breath and palpitations and was initially treated for symptomatic anemia due to vitamin B12 deficiency. He was referred for further evaluation after a blood smear showed rare blasts concerning for leukemia.<br /><br />On arrival, his CBC demonstrated pancytopenia with severe leukopenia, macrocytic anemia, and thrombocytopenia. His workup for infectious causes, including HIV, hepatitis B and C, parvovirus, EBV, and CMV, was negative. Repeat smear showed 8% myeloblasts. Because vitamin B12 deficiency can cause pancytopenia and abnormal smear findings that resemble malignancy, the team pursued bone marrow biopsy to clarify the diagnosis.<br /><br />The biopsy revealed a hypercellular marrow with 26–30% blasts showing a myeloid phenotype and CD56 expression, findings consistent with acute myeloid leukemia (AML). After discussion at tumor board, he was diagnosed with AML and started on decitabine and venetoclax.<br /><br />The report highlights the diagnostic challenge of distinguishing severe vitamin B12 deficiency from AML, since both can produce pancytopenia, macrocytosis, and even bone marrow hypercellularity with blast-like changes. It emphasizes that vitamin B12 deficiency should remain in the differential diagnosis of pancytopenia and abnormal peripheral smears, even when leukemia is suspected. Bone marrow biopsy with cytomorphology and immunophenotyping is often necessary to rule out malignant causes, but severe nutritional deficiency may sometimes mimic or obscure leukemia-like findings.

Asset Subtitle

Katrina E. Olenwine

Meta Tag

Author List Katrina E. Olenwine, Nigel A. Ravida

Category Clinical Vignettes

Concept Vitamin B12 Deficiency

Concept Pancytopenia

Concept Acute Myeloid Leukemia

Concept Macrocytic Anemia

Concept Peripheral Blood Smear

Distinguished Non-Finalist

Presenter Organization Penn State College of Medicine

Presenting Author Katrina E. Olenwine

Track Adult

Keywords

Crohn’s disease

vitamin B12 deficiency

pancytopenia

macrocytic anemia

acute myeloid leukemia

myeloblasts

bone marrow biopsy

hypercellular marrow

CD56 expression

decitabine and venetoclax

Vitamin B12 Deficiency

Pancytopenia

Acute Myeloid Leukemia

Macrocytic Anemia

Peripheral Blood Smear