[Aplastic anemia and myelodysplasia: a not-always-easy distinction]

The differential diagnosis between Myelodysplasia and Aplastic anaemia may be sometimes difficult, because clinical and morphological features may appear similar. Two cases, a Myelodysplastic syndrome with hypocellular and an Aplastic anaemia with hypercellular BM aspirates, are described in this report. Reciprocal connections between these two pathological entities, some biological aspects and the value of BM biopsy are also discussed.