Differential diagnosis for pancytopenia with cellular bone marrow include the following except -

In megaloblastic anemia , RBCs WBCs & platelets decreases (pancytopenia) & the cellularity of the bone marrow increases from moderate to hypercellular.Ceain morphologic features are common to all forms of megaloblastic anemia. The bone marrow is markedly hyper- cellular and contains numerous megaloblastic erythroid pro- genitors. Megaloblasts are larger than normal erythroid progenitors (normoblasts) and have delicate, finely reticu- lated nuclear chromatin (indicative of nuclear immaturity) (Fig. 11-11). As megaloblasts differentiate and acquire hemo- globin, the nucleus retains its finely distributed chromatin and fails to undergo the chromatin clumping typical of normo- blasts. The granulocytic precursors also demonstrate nuclear- cytoplasmic asynchrony, yielding giant metamyelocytes. Megakaryocytes may also be abnormally large and have bizarre multilobed nuclei. In the peripheral blood the earliest change is the appear- ance of hypersegmented neutrophils, which appear before the onset of anemia. Normal neutrophils have three or four nuclear lobes, but in megaloblastic anemias they often have five or more. The red cells typically include large, egg- shaped macro-ovalocytes; the mean cell volume often is greater than 110 fL (normal, 82 to 92 fL). Although macro- cytes appear hyperchromic, in reality the mean cell hemoglo- bin concentration is normal. Large, misshapen platelets also may be seen. Morphologic changes in other systems, espe- cially the gastrointestinal tract, also occur, giving rise to some of the clinical manifestations. Referance : Exam preparatory manual for UGs -Ramdas Nayak page no-256 Ref Robbins 9/e pg 422