The bone marrow can be patchy - some sections with many cells and some with few. Perhaps that is what happened here??? If you are very concerned or your counts start dropping, request another BMB to see if the cellularity results are different.
53 yo female, dx 9/08, AA/hypo-MDS, subclinical PNH, ATG/CsA 12/08, partial response. small trisomy 6 clone, low-dose cyclosporine dependent