Cell maturation guidelines

 

General guidelines for examination of bone marrow samples:


 
The microscopic examination initially starts with a small magnification (10 x objective) to get a general impression of the cell density. This involves looking at areas with sufficient bone marrow particals. With this magnification the amount of megakaryocytes and megakaryoblasts present in the bone marrow can also been examined. It is important here that several slides from the bone marrow aspiration are viewed. Subsequently, with a higher magnification (oil immersion / 50 x objective), the distribution of the bone marrow systems, their morphological aspect, maturation characteristics and any other characteristics are further examined. To support this, all cells derived from hematopoiesis are counted in various cell-rich, preferably erythrocyte-poor image fields. Some abnormalities can be variable in numbers in different image fields, extra attention must be paid to this. It can even happen that a abnormality can only be found in 1 or a small part of 1 slide! All slides must also be screened in their entirety for the presence of possible metastasic diseases.
 
Morphological characteristics:
 

 

 

  pro erytroblast basophilic erytroblast orthochromatic erytroblast
  pro erythroblast basophilic erythroblast polychromatic erythroblast orthochromatic erythroblast
             
Diameter 14 – 20 µm 10 – 14 µm 8 – 14 µm 7 – 10 µm
             
Nucleus Has a round nucleus, more or less centrally located in the cell.
Chromatin pattern is fine-grained, sometimes with a slight tendency to clump.
1 to 3 nucleoli present, these can be inconspicuous and blue in color.
Has a round nucleus, centrally or eccentrically located in the cell.
Chromatin pattern is moderately granular, nucleoli are no longer present
Has a round nucleus, centrally or eccentrically located in the cell.
Chromatin pattern is clumpy.
Nucleoli are not present
Has a round or irregularly shaped nucleus, centrally or eccentrically located in the cell.
Chromatin pattern is highly clumped to completely structurally homogeneous (pyknotic).
Nucleoli are not present
             
Cytoplasm The cytoplasm is narrow, uniformly deeply basophilic and often has a perinuclear highlight.
Sometimes pseudopodies (cytoplasmic spurs) may be present.
No granulation is present.
The cytoplasm is slightly wider than that of the pro erythroblasts, a deeply basophilic color and often has a perinuclear highlight.
No granulation is present.
The cytoplasm is broad, somewhat irregular and is less basophilic, blue-grayish to blue-orange color.
No granulation is present
The cytoplasm is small, at most weakly basophilic with a clear pink translucency and has a blue-grayish to gray-orange color.
No granulation is present.

 

 
  myeloblast promyelocyt myelocyt metamyelocyt band neutrophil
             
Diameter 13 – 20 µm 18 – 25 µm 12 – 20 µm 10 – 16 µm 9 – 15 µm 9 – 14 µm
             
Nucleus Round to slightly oval nucleus with a diffuse chromatin pattern. 1 or more nucleoli. Round to slightly oval nucleus with a fine-grained chromatin pattern, eccentrically located. 1 or more nucleoli. Round to oval nucleus with a slightly coarser chromatin pattern (clearly recognizable chromatin network). Often slightly eccentric.
No nucleoli are present.
Indented or kidney-shaped nucleus, with a coarse chromatin pattern with clumping.
No nucleoli are present.
Band-shaped nucleus, often curved. Narrowest part wider than 1/3 part of widest part. Very coarse chromatin pattern with a lot of clumping.
No nucleoli are present.
Nucleus constricted in 1 to 4 places. Very coarse chromatin pattern with a lot of compactly clumping.
No nucleoli are present.
             
Cytoplasm The moderate basophilic cytoplasm is narrow with a sharply bordered edge, often with a lighter zone around the nucleus. No or less than 5 azurophilic granulae are present. A more abundant basophilic cytoplasm, with the presence of prominent clear Golgi zone. Heavy azurophilic or primary granulae are present, colored blue or purple. A relatively more abundant cytoplasm, neutrophilic (sometimes still light basophilic) in color.
Fine granulae are present, purple-red colored. Secondary granules (basophilic / eosinophilic) can be present.
A more abundant cytoplasm, neutrophilic in color. Fine granulae are present. Secondary granules (basophilic / eosinophilic) can be present. Abundant neutrophilic cytoplasm and irregular in structure. Fine granulae are present. Secondary granules (basophilic / eosinophilic) can be present. Abundant neutrophilic cytoplasm and irregular in structure. Fine granulae are present. Secondary granules (basophilic / eosinophilic) can be present.

 

   
  monoblast promonocyte monocyte  
         
Diameter 12 – 20 µm 13 – 20 µm 13 – 22 µm  
         
Nucleus Large nucleus rond, or lobulated with a diffuse chromatin pattern and 1-2 discrete nucleoli. Round to oval or lobulated nucleus with a fine chromatin structure, open network-like. Single nucleoli can be present. Lobulated nucleus, with a fine clumped chromatin structure, open network-like. No nucleoli.  
         
Cytoplasm The abundant cytplasm is (deep) basophilic, contains no granulae. The abundant cytoplasm is gray to blue-gray in color. Sometimes very small azurophilic granulae are present (like paprika powder). The cytoplasm is abundant, irregular in structure, sometimes contains some vacuoles, is gray (to blue-gray) in color. Sometimes some very small azurophilic granulae are present (like paprika powder).  

 

         
  lymphoblast lymphocyte plasma cell  
   
Diameter 11 – 19 µm 6 – 12 µm 15 – 20 µm  
         
Nucleus Round to slightly oval nucleus with a somewhat compact reticular chromatin pattern. 1 to 2 nucleoli, often less distinct. Clumped dark-stained and dense. No nucleoli present Round nucleus with a very dense, clumped chromatin often cartwheel or clock face arrangement. Eccentrically located in the cell  
Cytoplasm Very small often deeply basophilic, no azurophilic granulae present. Small slightly basophilic with a few or witout any granulae. The cytoplasm is large, basophilic to purple in color, with a pale zone (extensive Golgi zone)  
         

 

         
  megakaryoblast megakaryocyte platelet  
   
Diameter 20 – 30 µm 60 – 100 µm 1 – 2 µm  
         
Nucleus Round to oval nucleus, with a fine dense chromatin sructure and inconspicuous nucleoli. Strongly multi-lobulated nucleus with irregular lobes, connected with chromatin threads, with a clumped chromatin structure, open network-like.
No nucleoli.
No nucleus  
Cytoplasm Cytoplasm is scanty and deeply basophilic. Cytoplasma can be anything from basophilic to pink and can contain from none to abundant azurophilic granules Granulated