#00063177

A 17-year-old lady with learning difficulties and neuromuscular scoliosis presented with pancytopenia (hemoglobin 57g/L, MCV 103fL, white blood cell 1.7 x 10^9/L, neutrophils 0.7 x 10^9/L and platelets 99 x 10^9/L). The peripheral blood film showed macrocytosis, hypersegmented neutrophils and occasional fragments (not shown), consistent with severe vitamin B12 (145ng/L) and folate (<1.2µg/L) deficiencies. Intrinsic factor antibody was negative. Lactate dehydrogenase was markedly elevated (5160 U/L). The bone marrow aspirate showed hyperplastic megaloblastic erythropoiesis, a multinucleated erythroblast and giant metamyelocytes (arrows). The blood count abnormalities resolved within 4 weeks following vitamin B12 and folate replacement.