Granulocytic Maturation

Maturation is distinguished by :

• cell size
• N:C ratio
• chromatin pattern
• presence or absence of nucleoli
• cytoplamic quality
• presence of granules

Neutrophil Maturation Cycle :

Myeloblast → Promyelocyte → Myelocyte (last stage to divide) → Metamyelocyte → Band → Segmented Neutrophil

http://www.med-ed.virginia.edu

Myeloblast :

• size : 14-20 µm
• N:C 6:1
• round, oval, indented nucleus with thin chromatin strands
• basophilic cytoplasm
• 2-5 nucleoli

http://www.med-ed.virginia.edu

Promyelocyte :

• size : 15-22 µm
• N:C 3:1
• oval, round (eccentric) flattened nucleus with thin chromatin strands
• prominent nonspecific granules
• slightly coarse nuclear chromatin
• large prominent nucleoi

http://www.med-ed.virginia.edu

Myelocyte :

• size : 10-18 µm
• N:C 2:1
• red/purple, oval, indented, denser nucleus, clumped appearance
• specific small pink-purple granules
• last stage capable of dividing

http://www.med-ed.virginia.edu

Metamyelocyte :

• size : 10-15 µm
• N:C 1:1
• kidney bean nucleus (no nucleoli)
• cytoplasm is pale blue – pinkish tan
• small specific granules

http://www.med-ed.virginia.edu

Band :

• size : 9-15 µm
• C – or S -shaped nucleus with no filaments
• seen in a normal peripheral smear

http://www.med-ed.virginia.edu

Segmented Neutrophil :

• size : 9-15 µm
• 2-5 lobes of nucleus connected by filaments without visual chromatin
• cytoplasm – pale lilac
• main function : defense
• seen in a normal peripheral smear

http://www.med-ed.virginia.edu

Eosinophils :

• size : 10-16 µm
• N:C 1:2
• numerous large red-orange specific granules containing histamine
• response to parasitic, allergic, and hypersensitive reactions

http://www.med-ed.virginia.edu

Basophils :

• size : 10-14 µm
• N:C difficult to determine
• large purple-black specific granules
  • seem to obscure the large cloverleaf-shaped nucleus
• contain histamine and heparin
• responds to hypersensitive reactions