Human megakaryocyte size varies with anatomical site

Whole megakaryocyte, megakaryocyte cytoplasmic and nuclear size were evaluated in human bone marrow obtained from posterior iliac crest and rib of subjects undergoing thoracotomy for repair of hiatal hernia. In addition the nuclear DNA content (ploidy) of the cells from each site was measured. Significantly larger mean megakaryocyte (P less than 0.002), and megakaryocyte cytoplasmic volumes (P less than 0.002), and different volume distributions were observed in costal marrow compared to the iliac crest. No change in mean nuclear volume was found. This was paralleled by no significant difference in mean ploidy. This suggests that the variation in megakaryocyte size with anatomical site is determined by the concomitant volume of cell cytoplasm, but not the nuclear volume.