Hematology Lab: Granulocytic Series

Study Notes

Stages: myeloblast, promyelocyte, myelocyte, metamyelocyte, band, and mature granulocyte (ben)
Myeloblast: • 15-20 um in diameter • N:C ratio 4:1 • Cytoplasm: moderate blue, no granules • Nucleus: round to oval, extremely fine chromatin, reddish purple, 2-5 nucleoli • First stage, found in bone marrow
Promyelocyte: • 15-21 um in diameter • Cytoplasm: presence of primary (azurophilic) granules, blue to reddish purple • N:C ratio: 3:1 to 2:1
Myelocyte: • 12-18 um in diameter • Secondary granules (specific granules) begin to appear • Last stage capable of mitosis
Neutrophilic myelocyte: • pink specific granules
Eosinophilic myelocyte: • dirty orange to red granules
Basophilic myelocyte: • dark blue-purple specific granules

9-15 um in diameter
Sausage shape, narrow, horse shoe-shaped nucleus
Indentation in nucleus is 1/3 the diameter of the cell
Last stage found in bone marrow, first stage found in circulation (0-3% in circulation)

Stages: monoblast, promonocyte, and monocyte
Monoblast: • 12-20 um in diameter • Found in bone marrow, mature neutrophil • Cytoplasm: moderately basophilic or blue-gray • N:C ratio 4:1 • Nucleus: round or ovoid, light blue-purple, lacy chromatin, 1-2 nucleoli
Promonocyte: • 14-18 um in diameter • Cytoplasm: ground glass appearance • May contain dust-like azurophilic granules • Nucleus: oval, may have a single fold or fissure, 1 nucleoli
Monocyte: • 14-20 um in diameter • Cytoplasm: abundant, blue-gray, ground glass appearance due to many fine azurophilic granules • Irregular, presence of pseudopods • Nucleus: kidney-shaped, brain-like convolution, lacy chromatin, no nucleoli present

Lymphoblast: • 10-18 um in diameter • Cytoplasm: no granules, more abundant than myeloblast, moderate to dark blue • Nucleus: round to oval, contain 1-2 distinct nucleoli • N:C ratio: 4:1
Prolymphocyte: • Smaller than lymphoblast • Cytoplasm: moderate to dark blue, may contain occasional azurophilic granules • Round, ova or slightly indented, chromatin pattern is clumped, 1-2 nucleoli
Lymphocyte: • 8-10 um in diameter • Cytoplasm: light blue, scanty to moderate, with few azurophilic granules • Nucleus: purple, dense, clumped chromatin, round, eccentric, no nucleoli

Stages: megakaryoblast, promegakaryocyte, granular megakaryocyte, mature megakaryocyte, and platelet
Megakaryoblast: • 20-50 um in diameter • Cytoplasm: non-granular, blue, darker than myeloblast, with small, blunt pseudopods • Nucleus: round, oval, multiple nucleoli • N:C ratio: 10:1
Promegakaryocyte: • 20-60 um in diameter • Cytoplasm: more abundant, less basophilic, granules begin to form • Nucleus: multiple nucleoli are visible, irregular in shape, may show lobulation • N:C ratio: 4:1 to 7:1

Refers to the routine procedure that gives an approximation of the total number of leukocytes in the circulation
Function of the WBC is to provide immunity, the ability to resist infection
In a normal adult, WBC ranges from 4,000-11,000/mm3
A count above normal is called leukocytosis, while a count below normal is called leukopenia

Eosinophil: a granulocyte present at sites of allergic reaction and parasitic infection
Can be obtained indirectly by determining WBC count multiplied by the eosinophil differential
Normal range: 50-350 x 10^6/L or 0.5-3.5% of WBC
Eosinophilia: increased eosinophils above normal, causes include allergic reactions, parasitic infestation/infection, brucellosis, and certain leukemias
Eosinopenia: decreased eosinophils count, causes include hyperadrenalism, shock, and ACTH administration