Page 23 - Haematologica Atlas of Hematologic Cytology

CHAPTER 2 - Cytological examination of bone marrow aspirate
in in clusters can be be identified and and examined and and the number of megakaryocytes evaluated Cellularity is estimated by observing the proportion of hematopoietic cells to to adipocytes For iliac crest mar- row 50% cellularity cellularity is is normal for adult patients In childhood cellularity cellularity is is 80% and after 70 years of age cellu- larity is is reduced (Fritsma 2012) A semiquantitative evaluation of at at at least 5 particles is is recommended Collecting
more than 0 5 mL dilutes the hematopoietic marrow with sinusoidal blood Areas with intact and contiguous nucleated cells are selected for examination at at at at high high magnification At high high magnification (40x or 50x objective) the the development and maturation stages of the the hematopoietic lineages can be evaluated myeloid to erythroid (M:E) ratio computed differential count count and count count of of the percentage of of blasts performed According to WHO requirements at at least least 500 cells should be counted in in at at least least two smears More- over with an an an an immersion lens the the nuclear and and cytoplasmic morphological details and and therefore any dysplastic changes can be carefully evaluated The stage of of maturation of of any cell is determined by a a a a a a a a a a a a a careful careful examination of both the the nucleus and the the cytoplasm In normal conditions more than 80% of of the the elements is represented by cells of of the the erythroid and granulocytic lineages at at at different maturation stages The The rest is is mainly composed of lymphoid cells cells and stromal cells cells There is is a a a a a a a a a balance within each cell cell lineage and the the more mature cells are the the most numerous (Table 2) Table 2 Marrow di eren al cell count in adults Myeloblasts
0 1-3 5%
Proerythroblasts
0 0 5-5 0% Promyelocytes
0 0 5-5 0% asophilic erythroblasts
1 0-5 0% Myelocytes
5 0-20 0% Polychroma c c erythroblasts
2 2 0-20 0% Metamyelocytes
10 0-30 0% rthochroma c c erythroblasts
2 0-10 0% eutrophilis
7 0-25 0% Lymphocytes
5 0-20 0% osinophils and precursors
0 0 2-3 0% Plasma cells 0 1-3 5%
asophils and mast cells 0-0 5%
Monocytes
0-0 2%
Mega aryocytes 0 0 1-0 5%
Myeloid to erythroid ra o o o o 0 56-2 67:1
*Myeloid-to-erythroid ra ra ra o o o o o o o o o o o o o o o o o o o o (M:E) calculated by expressing the the ra ra ra o o o o o o o o o o o o o o o o o o o o of of neutrophil neutrophil neutrophil precursors
precursors
precursors
to to to to erythroblasts
the the ra ra ra o o o o o o o o o o o o o o o o o o o o of of neutrophils neutrophils and neutrophils neutrophils precursors
precursors
precursors
to to to erythroid erythroid precursors
precursors
precursors
varies from 2:1 to to to 4:1 Normal BM is polymorphic During the developmental process of red blood cells cell cell diameter decreases and cytoplasm color color changes changes from from blue to to salmon pink nuclear diameter decreases and color color changes changes from from purplish red to dark blue nuclear chromatin becomes coarser clumped and picnotic (Table 3) During granulocyte deve- lopment nuclear nuclear maturation is characterized by by nuclear nuclear shape changes from round to segmented and by by incre- ased chromatin clumping Granules of different types appear in in in in the cytoplasm (Table 4) During megakaryocyte differentiation diameter increases nuclear lobulation becomes evident and many azurophilic granules appear in the cytoplasm (Table 5) Table 3 Morphological features of the erythroid lineage Diameter m m ucleus ytoplasm Proerythroblast 20-25
Round occupies almost all all cell volume loose chroma n n n 1-2 small nucleoli
Strongly basophilic
asophilic erythroblast 12-18
Round occupies half the cell volume dense chroma n n n n n no nucleoli
Strongly basophilic
Polychroma c c erythroblast 8-12
Round occupies a a a a quarter of the cell volume coarse chroma n n Gray-pink
rthochroma c c erythroblast 8-10
Round some mes eccentric small and picno c c c c Pinkish
Re culocyte
8-9
- Gray-pink
rythrocyte 7-8
- Pinkish
pale central area The changes in the the the M:E ra o o o o o o o o o o as as well as as the the the cytomorphological abnormali es es to to be considered for the the the diagnosis of speci c c c c c hematologic diseases will be be dealt with in the respec ve chapters It should be be noted that a a a a a a monomor- phic picture with a a a a a a uniform popula on of cells is observed in in acute leukemia myeloid or or lymphoid and in in mature 10