|6 rare morphologic disorders of Neutrophils
Looking different? Could be due to underlying diseases
are the most common type of leukocyte in the blood.
The most important feature of the neutrophil is the highly lobulated nucleus.
In the mature neutrophil there are usually five lobes connected by fine strands of nuclear material.
In less mature neutrophils, the nucleus is less lobulated.
Diagram of Normal Neutrophil
X-chromosome or Barr body is a drumstick-shaped appendage of one of the nuclear lobes.
This structure is known as "drumstick chromosome".
Women have drumsticks in 3% or more of the polymorphonuclear leukocytes.
Diagram of Normal Neutrophil with Barr body
These are 6 rare conditions where neutrophils look different from its normal appearance:
1) Toxic Granulation:
Diagram of Neutrophil showing Toxic Granules
Toxic granules are dark blue to purple cytoplasmic granules in the metamyelocyte,band or neutrophil stage.
The granules may be numerous or few in number and are peroxidase positive.
There may be less peroxidase activity in toxic than in normal neutrophils.
Toxic granulation is found in severe infections or other toxic condition.
Normally neutrophil granules are tan to pink in color in neutrophil metamyelocytes, bands, and mature forms.
Even the non-specific or neutrophil granules which are dark blue on the promyelocyte stage normally lose their basophilia in the mature neutrophil, where they constitute about one third of the granules in the human.
Toxic granules are azurophil granules that have retained their basophilic staining reaction by lack of maturation, or that have developed increased basophilia in the mature neutrophil.
Increased basophilia of azurophil granules simulating toxic granules may occur in normal cells with prolonged staining time or decreased pH of the staining reaction.
Irregular basophilia of the cytoplasm is also common in toxic conditions and appears to reflect impaired cytoplasmic maturation.
If discrete, this focal basophilia is known as a Dohle inclusion body.
Cytoplasmic vacuoles are also signs of toxic change. The possibility of degeneration artifacts can be eliminated by making films from fresh blood free of anticoagulant. Vacuoles or irregular depletion of granules implies that phagocytosis has occurred.
Another toxic change in the neutrophil is the occasional appearance of several sharp of blunt spicules extending out from the nucleus.
2) Dohle Inclusion Bodies:
Diagram of Neutrophil showing Dohle inclusion body
These are small, oval inclusions in the peripheral cytoplasm of polymorphonuclear neutrophils, which stain pale blue with Wright’s stain.
They are remnants of free ribosomes or rough surfaced endoplasmic reticulum persisting from an earlier stage of development.
Originally, Dohle bodies were described as being prominent in scarlet fever, but they are seen in many other infectious diseases, in burns, in aplastic anemia, and following administration of toxic agents.
They frequently accompany toxic granulation in the neutrophil.
With the light microscope, Dohle bodies resemble the inclusions seen in the May-Hegglin anomaly.
3) May-Hegglin Anomaly:
Diagram of Neutrophil in May-Hegglin anomaly showing pale blue inclusions
This is a rare autosomal dominant condition characterized by the presence of pale blue inclusions resembling Dohle bodies in neutrophils, giant platelets, and, in some persons, thrombocytopenia.
The inclusions are larger and more prominent than the Dohle bodies found in infections.
They have been described in eosinophils, basophils, and monocytes as well as neutrophils.
With electron microscopy, the appearance of the inclusions differs from that of Dohle bodies, suggesting structural alterations in RNA.
4) Alder-Reilly Anomaly:
Diagram of Neutrophil in Alder-Reilly Anomaly showing dense azurophilic granules.
In 1939 Alder described dense azurophilic granules in white blood cells.
In 1941, Reilly described similar granulocytes in some patients with gargoylism (Hurler's syndrome or mucopolysaccharidoses Type1)
The neutrophils may resemble toxic granulation.
It is not related to infection and is not transient in nature.
Other observations have shows that the heavy granulation in neutrophils can occur either as a feature of the genetic mucopolysaccharidoses or independently in otherwise healthy persons.
5) Pelger-Huet Anomaly:
Diagram of Neutrophil in Pelger-Huet anomaly with band shaped nuclei and coarse granules
This hereditary, autosomal dominant condition involves failure of normal segmentation of granulocytic nuclei.
Most nuclei are band shaped or have two segments but no more.
The chromatin is quite coarse, and are not normal young band forms.
When a large number of band neutrophils appear in the differential count in a patient without infection or other cause, careful analysis of the blood films of the patient and of family members will occasionally establish the presence of the Pelger-Huet anomaly.
An acquired disorder of the nuclear segmentation in granulocytes may occasionally be found in cases of leukemia, myeloproliferative disorders, some infections, and after exposure to certain drugs.
This disorder is sometimes called the pseudo-Pelger anomaly.
In addition to the band forms and neutrophils with only two segments, mature cells with round non-segmented nuclei and coarse chromatin are common, in contrast to the congenital Pelger-Huet anomaly.
6) Chediak-Higashi Syndrome:
Diagram of Neutrophil in Chediak-Higashi Syndrome showing abnormal large granules.
This rare, autosomal recessive disorder is characterized by partial albinism, photophobia, abnormally large granules in leukocytes and other granule-containing cells, and frequent pyogenic infections.
Lymphoma-like phase occurs, with lymphadenopathy, hepatosplenomegaly, and pancytopenia, lymphoid infiltrates are widespread and death occurs at an early age.
Granulocytes, monocytes, and lymphocytes contain giant granules which appear to be abnormal lysosomes.
Leukocyte functional abnormalities are present.
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