with vitamin B12 or folate deficiency due to inadequate uptake,
excessive usage, absorption problem, GI surgery or medication;
Serum LDH often
Megaloblastic anemia with numerous ovalocytes, and often
hypersegmented neutrophils. However, MCV may be within normal
range in some cases;
hypercellular marrow with marked erythroid hyperplasia and left
precursors with megaloblastic changes: large regular nuclei and
fine chromatin. Compared to cytoplasm, the nuclear maturation is
delayed since both vitamin B12 and folate are important in DNA
hypersegmented neutrophils and giant bands or metamyelocytes.
changes may be present.
megaloblastoid changes: Megaloblastoid erythroid precursors
typically show irregular nuclear contours, coarse and clumped
chromatin, and more obvious dysplastic cytological features. The
nuclei are often relative more mature than the cytoplasm.
hypercellular marrow with sheets of immature erythroid cells on
the core biopsy may closely resemble AML. On the tissue sections,
the early erythroid precursors are large in size and have high N/C
ratio, and importantly, the nuclei are usually very round with
clear chromatin and a central large nucleolus.