Page 51 - Clinical Hematology Atlas
P. 51

CHAPTER 4  MEGAKARYOCYTE MATURATION    35

                                            MEGAKARYOBLAST (MK-I)

                                                                                        Cytoplasm
                                                                Nucleoli


















                                                                                        Nucleus
                                                              B
                 A                                            FIGURE 4–2B  Megakaryoblast, schematic.
               FIGURE 4–2A  Megakaryoblast, MK-I—bone
               marrow (31000).


               SIZE:  10-24 mm
               NUCLEUS:  Round
               Nucleoli:  2-6
               Chromatin:  Homogeneous, loosely organized
               CYTOPLASM:  Basophilic
               Granules:  Absent by Wright stain
               N/C RATIO:  3:1
               REFERENCE INTERVAL:
               Bone Marrow:  20% of megakaryocyte precursors in
                  bone marrow
               Peripheral Blood:  0%



               NOTE:  The megakaryoblast appears similar to the
                  myeloblast and pronormoblast, and identification
                  by morphology alone is not advisable.
   46   47   48   49   50   51   52   53   54   55   56