Hematology and Clinical Microscopy Glossary - College of American ...

adjacent to the nucleus, indicating the location of the
Golgi apparatus. The cytoplasm is relatively more abundant
than in earlier precursors and is amphophilic. Both
azurophilic and specific granules are present in the cytoplasm
with specific granules coming to predominate as
maturation progresses.
Neutrophil, Metamyelocyte
Metamyelocytes are the first of the postmitotic
myeloid precursors. They constitute 15% to 20% of
nucleated cells in the bone marrow and may be seen in
the blood in pathologic states and in response to stress.
They are approximately 10 to 18 μm in diameter. They
are round to oval with a nuclear-to-cytoplasmic ratio
of 1.5:1 to 1:1. The nuclear chromatin is condensed and
the nucleus is indented to less than half of the potential
round nucleus (i.e., the indentation is smaller than half
of the distance to the farthest nuclear margin). The
cytoplasm is amphophilic containing rare azurophilic or
pink (primary) granules and many fine bluish or specific
granules.
Neutrophil, Giant Band or Giant
Metamyelocytes
Myeloid precursors that are a result of megaloblastic
hematopoiesis are increased in size and have nuclei
that show aberrant maturation where the nuclear
features appear less mature than the cytoplasmic
features. Although these changes are usually discussed
in terms of the neutrophil series, they may also be
observed in cells in the eosinophil and basophil cell lines.
Larger-than-normal metamyelocytes and bands with
decreased chromatin clumping are seen in the marrow.
These cells have diameters 1.5 times those of normal
metamyelocytes or bands.
Neutrophil, Segmented or Band
Band neutrophils, also known as stabs, and segmented
neutrophils constitute 12% to 25% of the nucleated cells
in the bone marrow. Band neutrophils constitute 5% to
10% of the nucleated cells in the blood under normal
conditions. Increased numbers of bands appear in the
blood in a number of physiologic and pathologic states.
The band is round to oval and 10 to 18 μm in diameter.
The nuclear-to-cytoplasmic ratio is 1:1.5 to 1:2 and the
nuclear chromatin is condensed. The nucleus is indented
to more than half the distance to the farthest nuclear
margin, but in no area is the chromatin condensed to a
single filament. The nucleus can assume many shapes: it
can be band-like; sausage-like; S, C, or U-shaped; and
twisted and folded on itself. The cytoplasm is similar to
that of other postmitotic neutrophilic cells, with specific
granules predominating in the pale cytoplasm.
Bone Marrow Cell Identification
The segmented neutrophil, the mature cell of the
myeloid series and the predominant white cell in blood,
mimics its immediate precursors in size (10 to 15 μm),
shape (round to oval), and cytoplasmic appearance
(pale pink cytoplasm with specific granules). The N:C
ratio is 1:3, the most mature of any cell in the
neutrophilic series, and the nuclear chromatin is
condensed. The nucleus is segmented or lobated
(two to five lobes normally). The lobes are connected
by a thin filament that contains no internal chromatin,
giving it the appearance of a solid, thread-like dark line.
The presence of these thread-like filaments is the basis
for distinguishing the segmented neutrophil from its
precursor, the band neutrophil. However, in repeated
proficiency testing studies, it has not been possible to
achieve consistent differentiation between bands and
segmented neutrophils. Therefore, for the purposes of
proficiency testing it is not required that they be
differentiated. (For a detailed guideline for the
differentiation of segmented and band neutrophils,
see Glassy, 1998).
Neutrophil, Toxic (Includes Toxic
Granulation and/or Döhle Bodies,
and/or Toxic Vacuolization)
Toxic changes in neutrophils include toxic granulation,
toxic vacuolization, and Döhle bodies. Toxic granulation
and Döhle bodies each may be present in an individual
cell without the other finding; either change alone is
sufficient to designate a neutrophil as “toxic.” Toxic
granulation is the presence of large purple or dark blue
cytoplasmic granules in neutrophils, bands, and
metamyelocytes. Vacuoles within the cytoplasm of
these same cells constitute toxic vacuolization.
The vacuoles are variable in size and may coalesce,
sometime distorting the neutrophil cytoplasm to
form pseudopodia. EDTA storage may produce
degenerative vacuolization; in this case, only a few,
small, punched-out appearing vacuoles are found.
However, as it may at times be difficult to distinguish
toxic from degenerative vacuoles, it is best not to
consider neutrophil vacuoles to be toxic unless
accompanied by other toxic changes. Döhle bodies
appear as single or multiple blue or gray-blue
inclusions of variable size (0.1 to 5.0 μm) and shape
(round, or elongated or crescent shaped) in the
cytoplasm of neutrophils, bands, or metamyelocytes.
They are often found in the periphery of the cytoplasm,
near the cell membrane. These inclusions represent
parallel strands of rough endoplasmic reticulum. In the
May-Hegglin anomaly, inclusions that resemble Döhle
bodies are seen, but in this heritable condition, the
inclusion is due to accumulation of free ribosomes and
the presence of 7 to 10 nm parallel filaments. Toxic
800-323-4040 | 847-832-7000 Option 1 | cap.org
25