Univ of Minn, Hematography Plus. http://www1. umn
Granulopoiesis The Crookston Collection. Granulopoioesis.
Myeloblast The earliest recognizable myeloid cell is the myeloblast (10-20m dia) with a large round to oval nucleus. There is fine diffuse immature chromatin (without clumping) and a prominant nucleolus. The cytoplasm is basophilic without granules. Although one may see a small golgi area adjacent to the nucleus, granules are not usually visible by light microscopy. One should not see blast cells in the peripheral blood.
Promyelocyte The promyelocyte (10-20m) is slightly larger than a blast. Its nucleus, although similar to a myeloblast shows slight chromatin condensation and less prominent nucleoli. The cytoplasm contains striking azurophilic granules or primary granules. These granules contain myeloperoxidase, acid phosphatase, and esterase enzymes. Normally no promyelocytes are seen in the peripheral blood. At the point in development when secondary granules can be recognized, the cell becomes a myelocyte.
Myelocyte Myelocytes (10-18m) are slightly smaller than promyelocytes and have eccentric round-oval nuclei, often flattened along one side. The chromatin is fine, but shows evidence of condensation. Nucleoli may be seen in early stages but not in the late myelocyte. Primary azurophilic granules are still present, but secondary granules predominate. Secondary granules (neut, eos, or baso) first appear adjacent to the nucleus. In neutrophils this is the "dawn" of neutrophilia. Myelocytes are not normally found in the peripheral blood.
Metamyelocute Metamyelocytes (10-18m) are slightly smaller than myelocytes. They have kidney shaped indented nuclei and relatively dense chromatin, especially along the nuclear membrane. The cytoplasm is faintly pink with almost no blue background. Numerous secondary granules (neutro, eos, or baso) clearly outnumber primary granules. Zero to one percent of the peripheral blood white cells may be metamyelocytes (juveniles).
Band Bands, slightly smaller than juveniles, are marked by a U-shaped or deeply indented nucleus. Opposite sides or lobes are of roughly equal size or diameter. There is no nuclear constriction > than 1/2 the lobe diameter. The chromatin is heavily clumped and secondary or specific granules either neutrophilic or basophilic predominate. Normal band counts vary but are usually in the range of 0-6%.
Segmented PMN Segmented (segs) or polymorphonuclear (PMN) leukocytes (average 14 m dia) are distinguished by definite lobation with thin thread-like filaments of chromatin joining the 2-5 lobes. The chromatin of the segmented neutrophil is coarsely clumped and the cytoplasm is pink due to large numbers of secondary granules. In practice when examining peripheral blood, neutrophils are the only leukocytes to be divided into myelocyte, juvenile, band, and PMN stages. Eosinophils and basophils of all stages are lumped together in most instances.
Myeloblast
Myeloblast
Promyelocyte
Neutrophilic Myelocyte
Metamyelocyte
Metamyelocyte and Band
Eosinophilic Band
Seg, Meta, and Band
Lymphobalst
Prolymphocyte
Mature Lymphocyte
Immature Megakaryocyte Univ of Virginia. http://www.healthsystem.virginia.edu/internet/hematology/hessedd/normal-hematopoietic-cells/immature-megakaryocyte.cfm
Megakaryocyte Megakaryocytes undergo endomitosis - a process whereby DNA is duplicated without cell division. Thus MKs become polyploid during amplification. Most platelet forming MKs have a ploidy of 16N, (range 4N - 64N). MKs are the largest normally occuring cells in the marrow (35-160m)
Megakaryocyte Crookston collection
Megakaryocyte MDS: View of bone marrow showing mononuclear megakaryocyte.
Formation of Platelets Univ of Virginia, Dept of pathology
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NORMAL Blasts 3/97 Myeloblasts (not normal, these are from leukemia patient) PGL promyelocytes, look for azurophilic granules in immature mononulear cells (again from leukemia patient) CML #3 Chronic Myelogenous Leukemia. Mainly myelocytes, metamyelocytes, bands, and segs. Rare promyelocyte CML 1991 another case, mostly myelocytes