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A motile precursor cell of blood granulocytes found in bone marrow.



one of the types of cells in the hematopoietic tissue of the red bone marrow in vertebrate animals and in man. They are formed from hemocytoblasts and pass through the promyelocyte stage. Granular leukocytes, or granulocytes, develop from myelocytes. The nuclei of myelocytes are round or bean-shaped and less compact than in mature leukocytes; the cytoplasm is weakly basophilic. Myelocytes do not normally enter the bloodstream, but in certain pathological conditions, such as leukemia, they may appear in the blood.

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The myeloid stem cells begin with myeloblasts or myelocytes, which are immature blood cells found only in the bone marrow, then further differentiate into more mature cells (such as the erythrocytes or red blood cells [RBCs]) and polymorphonuclear granulocytes (such as neutrophils, eosinophils, and basophils), monocytes, and platelets (Guyton & Hall, 2000).
Morphologic Features of t(8;21) and inv(16) Acute Myeloid Leukemia t(8;21) inv(16) * Large myeloid blasts with * Variable number of eosinophils abundant basophilic cytoplasm * Numerous azurophilic granules * All stages of eosinophilic maturation * Perinuclear clearing or hofs * Immature purple-violet cytoplasmic granules * Occasional blasts containing * Mainly evident at the Auer rods promyelocyte and myelocyte stages Table 2.
The control patients demonstrated a slightly higher percentage of myelocytes than did the patients with MDS (P [is less than] .
Consecutive phases vary, giving rise to a kinetically distinct mitotic pool in which numbers expand to include the myeloblasts, progranulocytes and myelocytes - loosely referred to as the fixed components of the microenvironment.
9]/l (check every 2 weeks until Basophils <5% CHR, then 3-monthly) No myelocytes, promyelocytes, myeloblasts in the differential count Platelet count <450x[10.
Most of the increases were caused by an increase in polymorphonuclear cells (PMN), but seven of nine subjects demonstrated myelocytes, a potentially clairvoyant observation given recent evidence that circulating stem cells increase after exercise (74).
Cells were pre-classified into: band neutrophils, segmented neutrophils, lymphocytes, monocytes, eosinophils, basophils, metamyelocytes, myelocytes, promyelocytes, blast cells, lymphocyte variant forms and plasma cells.
There was abnormal maturation of the myeloid lineage with an expanded mitotic pool (6% myeloblasts) and markedly increased numbers of promyelocytes and myelocytes.
The term chloroma comes from the green color of the immature myelocytes that are imparted by the enzyme myeloperoxidase in the cytoplasm.
8 White cell count (per mL) 21,300 Differential count (%) Neutrophils 31 Lymphocytes 45 Bands 12 Myelocytes 4 Metamyelocytes 2 Reactive lymphocytes 5 Platelet count (per mL) 156,000 Prothrombin time (s) 25.
Wright staining of a bone marrow smear showed large (2-4 [micro]m) round-to-oval, hyaline-structured eosinophilic granules (pseudo Chediak-Higashi [PCH] granules) within 15% of the blast cells, promyelocytes, and myelocytes (Figure).