Chapter 2 Thrombocytopoiesis
Figure 2-1 MEGAKARYOCYTOPOEISIS AND MEGAKARYOCYTES.
A, Megakaryoblast (stage I) with intermediate ploidy level. Cytoplasm is scant. Note prominent cytoplasmic pseudopods. B, Promegakaryocyte with early platelet production (stage II). C, Mature, high-ploidy megakaryocyte (stage III or IV) with abundant cytoplasm. Note cells traveling through cytoplasm. This is referred to as emperipolesis and is not uncommonly seen in large megakaryocytes. D, Portion of megakaryocyte cytoplasm in a long strand. Fragments of these can sometimes be seen in the blood and are referred to as proplatelets. E, Megakaryocyte nucleus denuded of its platelets and cytoplasm. F, Mature megakaryocyte seen in a tissue section of bone marrow biopsy. G,