Haematopathology

THE ANAEMIASDr Brian Mitchelson

Qatar Cardiovascular Research Centre

Digital Imaging Systems in

Pathology

Today in Qatar we use some of the most advanced digital

imaging technology available in the world for the diagnosis of

disease and in the research into these diseases.

Imaging in Haematopathology

From this

.

Through this

To this:

The Digital Microscope

Old Style Electron Microscopy

The Benchtop Electron Microscope

The Confocal Laser Microscope

Why do we need this level of technology?

Haematopathology consists of a series of dysplastic or

neoplastic changes to the body’s normal haematogenisis

and homeostasis.

These changes can be broken down into 4 main

haematological categories:

1. The Anaemias

2. Myeloid Neoplasms

3. Lymphoid Neoplasms

4. Histiocytic and Dendritic Neoplasms

Each category contains many different diagnostic

entities resulting in nearly 100 different types of

hematopoietic disorders and cancers.

Each different type has it own defining morphology,

pathobiology, treatment, and prognostic features.

Correct classification, as well as identification of

additional factors that may influence prognosis or

response to chemotherapy, is essential to allow the

optimal treatment.

Diversity of Disease

There are multiple different diseases of the

haematopoietic system including hereditary and

congenital disorders as well as acquired disorders.

Hereditary and congenital disorders include bone marrow

failure syndromes and primary deficiency syndromes.

Acquired disorders may be related to nutritional

deficiencies (such as iron, folate, and B12 deficient

anaemias), infectious processes or neoplastic disorders

Diseases of the hematopoietic system generally show

up as:

decreases in the normal values (anaemias)

or

increases in specific cell types

(lymphomas/leukemias)

Consequently, the tests most frequently used for

evaluation are:

peripheral blood smears, bone marrow aspirates or

biopsies, and lymph nodes biopsies to determine the

nature of the disease.

The ANAEMIAS

There are 3 major types of anaemia:

1. Anaemias due to blood loss

2. Anaemias due to poor or faulty red cell

production

3. Anaemias due to red cell destruction

Descriptive Terms used

for Red Blood Cells.

1. Anaemias due to blood loss

Apart from surgical or traumatic blood loss this can

also be due to gastrointestinal conditions such as

ulcers, hemorrhoids, gastritis (inflammation of the

stomach), and cancer.

Use of nonsteroidal anti-inflammatory drugs

(NSAIDs) such as aspirin or ibuprofen, which can

cause ulcers and gastritis.

Menstruation and childbirth in women, especially if

menstrual bleeding is excessive and if there are

multiple pregnancies.

Parasitic infections in children.

Coagulopathies.

Blood loss anaemia shows up on a

blood film as a markedly

regenerative anemia with frequent

large polychromatic erythrocytes

(reticulocytes) and increased

anisocytosis.

A nucleated erythrocyte is present

in the upper left and a basophilic,

spherical Howell-Jolly body

Blood Loss Anaemia

2.Anaemias due to poor or faulty

red cell production

With this type of anemia, the body may produce too few blood cells or the

blood cells may not function correctly.

In either case, anaemia can result.

Red blood cells may be faulty or decreased due to abnormal red blood

cells or a lack of minerals and vitamins needed for red blood cells to

function correctly.

Conditions associated with these causes of anaemia include the following:

Iron-deficiency anaemia

Vitamin deficiency

Bone marrow and stem cell abnormalities

This table shows the major causes

of iron deficiency and other

deficiency anaemias

Iron Deficiency and other Anaemias.

Note that in a blood film there is in

addition to the small (microcytic)

cells and hypochromic cells (with

increased areas of central pallor).

A variety of other shape

abnormalities are also present

(keratocytes, schistocytes).

Iron Deficiency Anaemia

This blood film shows a classical

iron deficiency anaemia picture of

hypochromic microcytic cells.

Iron Deficiency Anaemia

Bone marrow cells in anemia due

to Vitamin B12 deficiency.

The red blood cells and white blood

cells are large because Vitamin

B12 is required for normal

development.

The normal proliferation of cells

depends on adequate folate and

vitamin B12.

Folate is necessary for efficient

thymidilate synthesis and

production of DNA.

B12 is needed to successfully

incorporate circulating folic acid into

developing RBCs; retaining the

folate in the RBC.

Vitamin B12 and/or Folate Deficiency

This blood film shows the presence of

Oval Macrocytes and

Hypersegmented Neutrophils in

Vitamin B12 Deficiency

Vitamin B12 Deficiency

3. Anaemias due to red cell destruction

Haemolytic anaemia is a condition in which red blood cells

are destroyed and removed from the bloodstream before their

normal lifespan is up.

A number of diseases, conditions and factors can cause the

body to destroy its red blood cells.

Haemolytic anaemia can lead to various health problems such

as fatigue, pain, arrhythmias, an enlarged heart and heart

failure.

There are many types of haemolytic anaemias – some of

which are inherited and others that are acquired.

Haemolytic Anaemias

Inherited haemolytic anaemias include:

Sickle cell anaemia

Thalassemia

Hereditary Spherocytosis

Hereditary Elliptocytosis

Glucose-6-phosphate dehydrogenase (G6PD) deficiency

Pyruvate Kinase deficiency

This diagram shows the difference

in shape between the normal red

blood cell and the sickle cells.

Sickle cell anaemia

Normally, mature erythrocytes have a

rounded, biconcave shape that is

flexible enough for the small cells to

squeeze through even the smallest of

blood vessels.

With sickle cell anemia, however, many

red blood cells assume a rigid sickle-like

shape that can hinder their passage

through small capillaries.

Sickled red blood cells are unusually

fragile and prone to breakage, so they

only survive in the bloodstream for

about a tenth of the time that normal

erythrocytes remain in circulation,

increasing the effects of anaemia.

Sickle cell anaemia

Beta thalassemia minor, blood film.

Frequent poikilocytes. Tear drop-

shaped cells.

Hypochromia and basophilic

stippling.

The latter finding is nearly always

evident in thalassemia minor and is

not a feature of iron deficiency

making it a useful distinguishing

finding between these two

hypochromic-microcytic anaemias.

β Thalassemia Minor

Beta thalassemia major blood film.

The red cells are severely microcytic

on average.

Hypochromic cells are prevalent.

There is marked anisochromia (well

and poorly haemoglobinized red cells)

and marked anisocytosis (very small

and near normal sized red cells).

Misshapen cells are frequent including

tear drop, oval, elliptical, and

fragmented cells.

A nucleated red cell is evident as is a

lymphocyte.

β Thalassemia Major

Hereditary spherocytosis

Hereditary spherocytosis (also known as Minkowski– Chauffard

syndrome) is a non immune-mediated haemolytic anemia

characterized by the production of red blood cells that are sphere-

shaped (spherocytosis) rather than the normal biconcave disk

shaped RBCs.

This difference in shape makes the red blood cells more prone to

rupture.

The disorder is inherited as an autosomal dominant.

On a blood smear, Howell-Jolly bodies may be seen within red blood

cells.

Hereditary spherocytosis (HS) is a familial

haemolytic disorder associated with a

variety of mutations that lead to defects in

red blood cell (RBC) membrane proteins.

The morphologic hallmark of HS is the

microspherocyte, which is caused by loss

of RBC membrane surface area and has

abnormal osmotic fragility in vitro.

The blood film shows numerous dense

microspherocytes.

Hereditary Spherocytosis (HS)

Hereditary Elliptocytosis, also known

as ovalocytosis, is an inherited blood

disorder in which an abnormally large

number of the patient's erythrocytes

are elliptical rather than the typical

biconcave disc shape.

It is one of many red-cell membrane

defects.

In its severe forms, this disorder

predisposes to haemolytic anaemia.

Note the range of shape changes from

oval (arrow) to elliptical (asterisk).

Some cells are very small and

distorted. Most cells maintain their

biconcavity, even the small cells.

Hereditary Elliptocytosis

G6PD deficiency is an X-linked recessive

genetic deficiency characterized by

abnormally low levels of glucose-6-

phosphate dehydrogenase.

G6PD is the rate-limiting enzyme in the

pentose phosphate pathway. This,

deficiency of the G6PD enzyme results in

reduced glutathione making the red cells

vulnerable to oxidative damage and thus

liable to haemolysis.

The two arrows points to keratocytes or

“bite” cell, characteristic of haemolytic

disease induced by oxidative stress in

patients with this red cell enzyme deficiency.

The deformity is thought to be the result of

oxidative damage that leaves a segment of

the cell appearing as if a bite was taken out

of it.

Glucose-6-Phosphate Dehydrogenase

(G6PD) Deficiency

Pyruvate kinase deficiency is an inherited disorder

that affects red blood cells. In people with

pyruvate kinase deficiency, haemolytic anaemia

and associated complications may range from

mild to severe.

Pyruvate kinase deficiency is the most common

inherited cause of nonspherocytic haemolytic

anaemia.

The precise mechanisms that cause

extravascular haemolysis are as yet unknown, but

an important feature involves the selective

sequestration of PK-deficient young red blood

cells, in particular reticulocytes, by the spleen.

This disorder does not have diagnostic red

cell changes on the blood film. Macrocytic

polychromatic cells are reticulocytes, which are

usually increased in proportion.

Pyruvate Kinase Deficiency

Acquired haemolytic anaemias include:

Immune haemolytic anaemia

Autoimmune haemolytic anaemia

Alloimmune haemolytic anaemia

Drug-induced haemolytic anaemia

Mechanical haemolytic anaemias

Paroxysmal nocturnal haemoglobinuria

Certain infections and substances can also damage red

blood cells and lead to a haemolytic anaemia

Immune Haemolytic Anaemia

Immune haemolytic anemia occurs

when antibodies form against the body's

own red blood cells and destroy them,

because the immune system mistakenly

recognizes these blood cells as foreign.

A blood film shows a background of

spherocytes characteristic of this

immune haemolytic anemia.

Top image:

Erythrophagocytosis of a spherocyte by

a neutrophil.

Bottom image:

Neutrophil containing a red cell ghost

(haemolyzed red cell).

Autoimmune haemolytic anemia is classified as

primary or secondary and is subclassified according to

autoantibody type.

In primary autoimmune haemolytic anemia, no

underlying systemic disease explains the presence of

autoantibodies, whereas secondary autoimmune

haemolytic anemia results from a systemic disease.

The autoantibody may be immunoglobulin G (IgG),

immunoglobulin M (IgM), or, rarely, immunoglobulin A

(IgA); it may be warm reacting or cold reacting.

The peripheral blood smear shows several clumps of

RBCs with the largest in the center. These are typical

of aggregates seen in persons with cold agglutinin

disease.

Autoimmune Haemolytic Anaemia

This type of haemolytic anaemia occurs if your

body produces antibodies against red blood

cells that you get from a blood transfusion.

This can happen if the transfused blood is a

different blood type from your blood.

This type of haemolytic anaemia can occur

during pregnancy if a woman has Rh-negative

blood and her baby has Rh-positive blood.

The blood film shows reticulocytes, nucleated

red cells, and the ejected erythroblast nuclei.

Spherocytes are present.

The intense erythroblastosis (nucleated red

cells in the blood) is characteristic of Rh-

mediated alloimmune haemolysis.

Alloimmune Haemolytic Anaemia

Certain medicines can cause a reaction that develops into

haemolytic anemia.

Some medicines, such as penicillin, bind to red blood cell

surfaces and can cause antibodies to develop.

Other medicines cause haemolytic anemia in other ways.

Examples of these medicines include chemotherapy,

acetaminophen, quinine and antimalarial medicines, anti-

inflammatory medicines, and levodopa.

The blood film shows a similar picture to the alloimmune

haemolytic anaemias with evidence of some red cell

regeneration.

Drug-induced Haemolytic Anaemia

Fragmented red blood cells seen

on a blood film.

This was from a case of

mechanical haemolytic anaemia

where a mitral valve repair of the

heart caused the destruction of the

red cells.

Mechanical Haemolytic Anaemias

Fava Bean-Induced Haemolysis, this is

an example of one of the substances

and infections which can cause a

haemolytic anaemia.

Anisocytosis resulting from presence of

reticulocytes and smaller poikilocytes is

seen.

Characteristic keratocytes (bitten or

helmet cells) are present reflecting

oxidant-induced hemolysis.

Spherocytes or keratospherocytes are

often present.

The haemolysis is induced by the

oxidative stress on the Rbcs caused by

the Fava Bean protein.

Fava Bean-Induced Haemolysis

Histiocytic and

Dendritic NeoplasmsThese are rare neoplasms arising from phagocytic and dendritic cells and constitute less than 1% of all lymphoid/myeloid neoplasms.The WHO classify these into 6 categories:

§ Histiocytic sarcoma

§ Langerhans cell histiocytosis

§ Langerhans cell sarcoma

§ Interdigitating dendritic cell sarcoma/tumor

§ Follicular dendritic cell sarcoma/tumor

§ Dendritic cell sarcoma, not otherwise specified

Histiocytic Sarcoma HS

Histiocytic sarcoma (HS) is an extremely rare non-Langerhans histiocyte disorder of unknown cause that most commonly presents with symptoms due to unifocal or multifocal extranodal tumors.

It is not age or gender specific but is often found in relationship with follicular lymphomas, myelodysplasia and acute lymphoblastic leukaemias.

When HS occurs in the context of another haematologic malignancy, the two entities are often clonally related.

(a) Cervical lymph node showed

islands and cords of the dendritic

cell neoplasm sharply segregated

from areas of CLL/SLL

(b) The dendritic cells have

abundant eosinophilic cytoplasm,

lobulated and indented nuclei,

vesicular chromatin and variably

prominent nucleoli.

Some cells showed highly

polylobulated nuclei. The

CLL/SLL cells were small with

round nuclei, coarse

chromatin and scant

cytoplasm.

Histiocytic Sarcoma HS

Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease involving clonal proliferation of Langerhans cells.

These are abnormal cells arising in the bone marrow and are capable of migrating from the marrow to the skin to lymph nodes.

Clinically, these neoplasms can range from isolated bone lesions to multisystem disease.The disease spectrum results from clonal accumulation and proliferation of cells resembling the epidermal dendritic cells called Langerhans cells, hence sometimes called Dendritic Cell Histiocytosis.

These cells in combination with lymphocytes, eosinophils, and normal histiocytes form typical LCH lesions that can be found in almost any organ

Langerhans Cell Histiocytosis

Mortality/MorbidityMore than half the patients younger than 2 years with disseminated Langerhans cell histiocytosis (LCH) and organ dysfunction die of the disease, whereas unifocal LCH and most cases of congenital self-healing histiocytosis are self-limited. Multifocal chronic LCH is self-limited in most cases, but increased mortality has been observed among infants with pulmonary involvement.RaceThe prevalence of Langerhans cell histiocytosis seems to be higher among whites than in persons of other races.SexThe frequency of Langerhans cell histiocytosis is greater in males than in females, with a male-to-female ratio of 2:1.Age(LCH) affects patients from the neonatal period to adulthood, although it appears to be more common in children aged 0-15 years (reportedly approximately 4 cases per million population). The age at onset varies according to the variant of LCH.

Focus of Langerhans cell

histiocytosis with classic histologic

appearance.

These cells have classic nuclear

folds and grooves with ample pale

pink cytoplasm.

This case was not rich in

eosinophils in this region.

Langerhans Cell Histiocytosis

Langerhans Cell Sarcoma

Langerhans Cell Sarcoma is a very rare subtype of Sarcoma.

So rare that there have probably been only 50 cases EVER documented.

It is not to be confused with Langerhans Cell Histiocytosis , which is another condition that occurs mainly in children, of which there more cases worldwide.

This is a rare cancerous growth of Langerhans cells that can develop in the lymph nodes, skin, liver, spleen and bones

Large mononuclear cells with oval

to folded nuclei, with prominent

nucleoli and abundant pink

cytoplasm.

The mitotic rate is high.

The immunoperoxidase studies

show histiocytic/dendritic origin.

Langerhans Cell Sarcoma

Interdigitating Dendritic Cell

Sarcoma (IDCS)

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare neoplasm that mainly arises from the lymphoid tissues of the immune system. Although this neoplasm typically occurs anywhere along the lymph nodes, it can also be found at extranodal sites, especially in the head and neck.

Although most dendritic cell sarcomas arise in the lymph nodes of the cervical, mediastinal, or axillary regions, approximately one-third of the cases involve extranodal sites such as the spleen, small intestine, skin, testis, ovary, urinary bladder, and tonsils .

Among extranodal sites, the occurrence in the head and neck area is especially low, and only eight cases in oral cavity have been reported.

IDCS is defined as a neoplastic proliferation of spindle-shaped to ovoid cells with phenotypic features similar to those of IDCs.

Interdigitating dendritic cell

sarcoma.

The cells show marked cytologic

atypia.

Interdigitating Dendritic Cell

Sarcoma (IDCS)

Follicular Dendritic Cell

Sarcoma/tumor

Follicular dendritic cell sarcoma (FDC sarcoma) is a very rare type of soft tissue sarcoma. Fewer than 100 cases have been reported in medical literature world wide.

Sarcomas are cancers that develop from the supporting tissues of the body. Supporting tissues include bone, cartilage, fibrous tissue, blood vessels, nerves and so on.

Follicular dendritic cell sarcoma develops from specialised cells in the lymph nodes. Most develop in the lymph nodes and are called nodal cancers. But about 3 out of 10 (30%) develop elsewhere in the body in the:Head and neckDigestive system (bowel, stomach)SpleenLiver

These FDC sarcomas are known as extranodal tumours, because they grow outside the lymph nodes and bone marrow.

Follicular dendritic cell sarcoma.

A greater than usual degree of

cytologic atypia is present.

Note the atypical mitotic figure.

Follicular Dendritic Cell

Sarcoma/tumor

Dendritic cell sarcoma,

not otherwise specified

Occasional dendritic cell neoplasms do not fall into well-defined categories, as defined previously.These have been called indeterminate cell sarcoma/tumor.

o Extremely rare cases reported

o Diagnosis of exclusion, not well characterized morphologically and immunophenotypically

o Tumors positive for CD1a and S-100 protein but without Birbeck granules have been called indeterminate neoplasms said to derive from a cell in transition between a Langerhans cell and an interdigitating dendritic cell

o In a recent large series with multiple markers and EM no cases of this category were found

End of Part 1

I would like to thank the following for the use of several images and data:Lichtman’s Atlas of HematologyThe American Society of HematologyWeill Cornel University