1. Dr. Mehdi Ashik Chowdhury
M.B.B.S. MD. (BSMMU)
Assistant Professor &
Head of the Department of Pathology
Tairunnessa Memorial Medical College
Leukaemia

2. Normal value of WBC in Adults
• Total leucocyte count: 4000—11000/c.mm
• Differential count : Percentage Absolute count
• Neutrophils 40—75 % 2000—7500/c.mm
• Lymphocytes 20—50 % 1500—4000/c.mm
• Monocytes 2—10 % 200—800/c.mm
• Eosinophils 1—6 % 40—400/c.mm
• Basophils < 1% 10—100/c.mm
• Leukocytosis : When total count is more than
11,000/c.mm in an adult.

3. Causes of Neutrophilia (When absolute
count is more than 7,500/c.mm)
• Infection, particularly acute infection with cocci
• Tissue injury due to infarction (MI), Burns, Surgery.
• Haemorrhage
• Neoplasia
• Stress states such as convulsions, Labour, Severe colic
• Inflammatory disorder such as Rheumatic fever,
collagen disease.
• Metabolic disorder such as diabetic keoacidosis
• Corticosteroid administration
• Misc.

4. • Causes of eosinophilia
1) Allergy to extrinsic agents such as dust, pollen,
drugs etc.
2) Parasitic infection : Ascaris, hookworm, filaria,
tapeworm etc.
3) Dermatologic condition such as pemphigus.
4) Neoplasia such as Hodgkin’s disease.
5) Loeffler’s syndrome.

5. • Causes of lymphocytosis
• When in adult the absolute count is more than
4000/c.mm then it is known as lymphocytosis.
• Causes are :
• Pertussis
• Viral infection such as infectious mononucleosis,
viral hepatitis etc.
• Chronic bacterial infection such as Tuberculosis,
Brucellosis and Syphilis.
• Chronic lymphocytic leukaemia.

6. • Neutropenia and Agranulocytosis
• Neutropenia: When blood neutrophil absolute count
is less than 2000/c.mm then it is kwown as
Neutropenia.
• Agranulocytosis: Complete or almost complete
absence of neutrophil.

7. • Causes of neutropenia :
• Replacement of normal marrow by neoplastic state
e.g: Acute leukaemia, lymphoma, multiple myeloma,
myelodysplasia, myelofibrosis.
• lnfection such as typhoid, Kala-azar, viral hepatitis.
• Overwhelming infection in which consumption of
neutrophils exceeds production.
• Cytotoxic therapy
• Felty's syndrome
• Hyperspleenism
• Drugs
• Aplastic anaemia

8. Leukaemia
• Leukaemia may be defined as neoplastic proliferation
of haematopietic cells causing progressively
increasing infiltration of bone marrow with or
without infiltration of other organ

9. • Classification
• Leukaemia is classified as :
• Acute and Chronic. Acute leukaemia are those where
more than 30% of the bone marrow cells are blast
cell. Acute leukaemia is divided into acute
myeloblastic leukaemia and acute Lymphoblastic
leukaemia. On the basis of FAB classification acute
myeloblastic leukaemia is again subdivided into
seven subgroups and acute lymphoblastic leukaemia
are subdivided into three subgroups.
• Chronic leukaemia is also classified as :
• Chronic myeloid leukaemia
• Chronic lymphoid leukaemia

10. • FAB classification of acute leukaemia :
• Acute myeloid leukaemia :
• M1 : Myeloblastic leukaemia without maturation.
Myeloblast with non-granular cytoplasm or rare
azurophil cytoplasm/ Auer rods.
• M2 : Myeloblastic leukaemia with maturation.
Promyelocyte and more mature myeloid cells in
addition to myeloblast.
• M3 : Most cells are promyelocytes with heavy
cytoplasmic granulation and reniform nuclei.
Multiple auer rods often in parallel bundles (faggots).

11. • M4 : Myelomonocytic leukaemia. Immature and
mature cells of both myeloid and monocytic lineage.
• M5 : Monocytic leukaemia
• M6 : Erythroleukaemia. Erythroblast more than 50 %
of marrow nucleated cells. Myeloblast and
promyelocyte increased.
• M7 : Megakaryocytic leukaemia.

12. • Acute lymphoblastic leukaemia :
• L1 : Homogenous small lymphocytes; scanty
cytoplasm, regular round nuclei, inconspicuous
nucleoli.
• L2 : Heterogenous lymphoblast; variable amount of
cytoplasm, regular round nuclei, large nucleolus.
• L3 : Large homogenous lymphoblasts; basophilic
cytoplasm, round nuclei, prominent nucleoli,
cytoplasmic vacuolation.

13. • Acute leukaemia.
• Clinical feature of Acute Leukaemia
• Common :
• Anaemia
• Fever
• Bleeding manifestation.
• Less common :
• Pain in bones and joints (Especially children)
• Infections
• Lymph node enlargement (Especially children)

14. Blood Picture of Acute Leukaemia
Hb% : Reduced
Blood film : RBC shows Anisocytosis and anisochromia.
There may be polychromatic RBC and nucleated RBC.
WBC usually shows increase in total count with left
shifting. But the total count may be normal or reduced.
Blast cells are the outstanding feature (Usually more than
30%). Platelets are reduced.

15. Bone marrow :
Cellularity : Hypercellular
Myeloid erythroid ratio : Increased.
Erythropoiesis : Depressed but normoblastic
Granulopoiesis : Hyperactive with most cells are
(More than 30%) blast.
Megakaryocytes : Reduced.

16. Subleukaemic leukaemia are leukaemia in
which peripheral blood film show immature WBC
but total count of WBC is normal or reduced.
Aleukaemic leukaemia : Leukaemia in which
peripheral blood film does not show any
abnormal cell but leukaemia is suspected from
clinical feature and confirmed by bone marrow.

17. The basic morphological features of myeloblast,
lymphoblast and monoblast are similar.They are usually
10 to 18 µm in diameter with a round to oval one or
more nucleoli. The cytoplasm is moderately to deeply
basophilic and contains few if any granules. The type
of leukaemia is determined by :
1) Morphological feature of leukaemic cells in the blood
and bone marrow film.
2) Cytochemical stain and estimation of serum lysozyme.
3) Study of cell surface marker with monoclonal antibody.

18. Myeloblast Lymphoblast
Morphological feature of leukaemic cell In blood and
bone marrow film

19. Difference between Myeloblast and
Lymphoblast
Myeloblast Lymphoblast
Larger cell Smaller cell
Cytoplasm more Cytoplasm less with higher
nuclear cytoplasmic ratio
Cytoplasm may contain granules Cytoplasm does not contain
granules.
Cytoplasm may contain Auer
rod
No Auer rod
Nucleoli more usually two to
six.
Nucleoli less usually one to two.
Nucleus is round to oval with
fine chromatin
Nucleus is round with more
condensed chromatin.

20. • Cytochemistry : Cytochemistry is an adjunct to
routine stain (Romanovsky stain) in determining the
type of anaemia. In acute leukaemia, the most useful
cytochemical stain and their reaction pattern with
immature cells are listed below :
• Myeloperoxidase and Sudan Black B : Positive in
myeloid series.
• Periodic acid schiff (PAS) : Positive in some
immature lymphoid cell and sometime in
erythroblast.
• Non-specific esterase : Positive in monocytic series.
• Acid phosphatase : Focal positive in T cell ALL and
diffuse reaction in monocytic series.

21. Myeloperoxidase
stain AML
Sudan Black B
stain ALL

22. PAS positive in ALL

23. Non-specific esterase positive in
Monocytic leukaemia

24. Serum Lysosome : Serum lysozyme level is highly
increased in myelomonocytic and monocytic leukaemia.
Cell surface markers : Antigen and receptors on the
surface of normal haemopoietic cells at various stages of
differentiation may also be present on leukaemic ‘blast’
cells of the same lineage. So it is also possible to classify
acute leukaemia by cell surface marker.

25. Chronic Granulocytic Leukaemia(CGL) /
Chronic Myeloid Leukaemia (CML)
• CGL or CML is a disease of middle life, majority
occuring between the ages of 30 and 60 years. It is
a type of myeloproliferative disease associated with a
characteristic chromosomal translocation called
the Philadelphia chromosome. Presenting
manifestation are Anaemia, Huge Spleenomegaly,
fatigue and weight loss. Other features may be night
sweat, bruising etc. Bruising may result either from
dysfunction of platelets or from reduction of platelets
in blastic crisis.

26. • Blood Picture :
• Hb % : Reduced.
• Total count of WBC : Markedly elevated.
• Blood Film :
• RBC : Normocytic normochromic with
anisopoikilocytosis. There may be nucleated RBC.
• WBC : Shows left shift with markedly elevated total
count and all the cells of myeloid series are present
predominantly myelocytes (More than 20%) and
neutrophil. Increased Basophil count (2 to 10%) is a
characteristic feature. Myeloblast are less than 10%.

27. CGL - PBF CGL-Bone marrow

28. • Cellularity : Hypercellular marrow with partial or
complete replacement of fat spaces.
• Myeloid erythroid ratio : Increased.
• Erythropoiesis : Depressed but normoblastic.
• Granulopoiesis : Hyperactive with left shift. Most
of cells are myelocyte.
• Megakaryocytes : Increased but are smaller than
normal.

29. Reciprocal translocation between chromosome 9 and 22
occur. Part of long arm of chromosome 9 is translocated
to chromosome 22 and long arm of chromosome 22 is
translocated to chromosome 9 resulting in formation of
elongated chromosome 9 and small chromosome 22. Here
chromosome 22 is known as Philadelphia chromosome.
Chromosomal study

30. • Phases of CGL
• 1) Chronic phase
• 2) Accelerated phase
• 3) Blast crisis.
• Blast crisis is a stage where the cell distribution
typical of acute leukaemia occurs. There is
appearance of large proportion of blast cell , a
falling haemoglobin and development of
thrombocytopenia. In chronic phase treatment is
relatively easy and patients response is good. Most of
the patient die due to blast crisis. In many of patient
the patient goes to accelerated phase. Accelerated
phase teminate into blast crisis.

31. • The importance of recognition of accelerated phase is
that the patient rapidly develop blastic crisis without
treatment. But the treatment during this phase is
relatively easier then blast crisis and some of the patient
may revert to chronic phase. The characteristic features
of accelerated phase are as follows
• Blast cells are 10 to 19%.
• Basophil percentage may rise more than 20%
• Platelet count more than 1000000 or may be less than
100000.
• Rapidly falling haemoglobin percentage.
• Any one or more of above feature indicate accelerated
phase.

32. Chronic Lymphocytic Leukaemia (CLL)
• CLL is a disease of middle and older age group (45 to
75 years). The onset of disease is characteristically
insidious. Common Presenting manifestation are :
• Superficial lymph node enlargement.
• Anaemia.
• Accidental discovery

33. • Blood Picture
• Hb% : Reduced.
• WBC : Count is usually markedly raised usually more
than 50,000/c.mm but count may be less than
10,000/c.mm.
• RBC : Normocytic Normochromic. There may be few
microsperocytes and polychromatic RBC (As there
may be associated autoimmune haemolysis).
• WBC : Markedly raised total lymphocyte count most
of which are mature small lymphocytes although in
some cases the lymphocytes are of medium size. The
cells have a monotonous appearance. Some smear
cells (Disrupted lymphocytes) are also present.
• Platelets are usually reduced.

34. • Bone marrow examination :
• Cellularity : Hypercellular marrow.
• Myeloid erythroid ratio : Increased.
• Erythropoiesis : Depressed but normoblastic.
• Granulopoiesis : Active and maturing to segmented
form.
• Megakaryocytes : Reduced.
• There is marked increase in lymphocytes.

35. Leukaemoid Reaction
• When peripheral blood film resembling leukaemia
but the subject does not have any leukaemia.
• Blood picture suggest leukaemia because of markedly
elevated total count or presence of immature cells in
blood film or both.
• Leukaemoid reaction is of two types :
• 1) Myeloid
• 2) Lymphoid.

36. Myeloid leukaemoid
reaction
Lymphoid leukaemoid
reaction

37. • Cause of myeloid leukaemoid reaction :
• Infections
• Non-haematological malignancy
• Acute haemolysis.
• Cause of lymphoid leukaemoid reaction :
• Pertusis (Whooping cough)
Infectious mononucleosis.
Cytomegalovirus infection.
Disseminated Tuberculosis.

38. Comparison between leukaemoid reaction
and leukaemia
Leukaemoid reaction Leukaemia
Clinical
feature
Clinical feature of
causative disorder often
obvious
Spleenomegaly, Lymph
node enlargement and
bleeding manifestation
more common.
Total count
of WBC
Increase but seldom
exceeds 100x109/l
Can exceeds 100x109/l
Proportion of
immature
cells
Few to moderate.
Myelocytes <15%
Blasts <5%
Usually numerous

39. Leukaemoid reaction Leukaemia
WBC
morphology
Toxic granulation may be
seen in infective cases
Toxic granulation
not seen
Anaemia May present but usually
mild.
Usually present and
progressive
Platelets Normal or increased Usually reduced
except in CGL.
Bone marrow Normal or hyperactive
Granulopoiesis but
proportion of immature
cells are normal.
Hyperactive
granulopoiesis and
large proportion of
immature cells
The confirmatory test is bone marrow examination

40. Leukoerythroblastic blood picture
• Presence of immature leukocytes and nucleated red
cells in the peripheral blood is known as
Leukoerythroblastic blood picture.
• Causes are :
• Secondary carcinoma of bone (Most common)
• Myelofibrosis
• Multiple myeloma
• Thalassaemia major especially after spleenectomy.
• Active haemolytic anaemia.
• Lymphoma.

41. Bone marrow failure
• Bone marrow failure is a condition in which there is
insufficient production of either RBC, WBC or platelets or all
three cell lines. The lymphocytes are usually spared. Causes of
bone marrow failure may be inherited or acquired. The causes
are :
• Inherited cause : Fanconi anaemia, dyskeratosis congenita,
Diamond-Blackfan anaemia.
• Acquired cause : Aplastic anaemia (Most common),
Myelodysplastic syndrome, Paroxysmal nocturnal
haemoglobinuria, Large granular lymphocytic leukaemia.

42. Myelodysplastic syndrome (MDS)
• It is a disorder of multipotent haemopoietic stem cells.
• It is characterized by various combinations of anaemia,
neutropenia and thrombocytopenia usually with a
normocellular or hypercellular bone marrow. They have
several features in common with acute leukaemia but
their clinical course tends to be more chronic and lesser
percentage of blast cells in the bone marrow (Less than
30%). They have a common tendency to evolve into
acute leukaemia.

43. • The majority of these patients are elderly and presents with marrow failure
despite normal or increased marrow cellularity. A hallmark of the disease is
ineffective erythropoiesis so that cytopenias often accompany a marrow of
normal or increased cellularity. There is also dyserythropoietic feature in
the bone marrow. The nomenclature of this syndrome have changed over
last 70 years. In 1930, the term ‘refractory anaemia’ was used to describe
the anaemic patient who were unresponsive to Iron, vitamin B12 or folic
acid. With the advent of Perls’ stain a subgroup of patient were shown to
have ring sideroblast in the bone marrow some of which subsequently
develop acute leukaemia. In 1950, it was appreciated that acute leukaemia
in the elderly was often preceded by a preleukaemic phase of peripheral
blood cytopenia associated with normal or slightly increased percentage of
bone marrow blasts. In 1982, the FAB group divide MDS into five
subgroups. This classification was based on percentage of blast and ring
sideroblast in the bone marrow and the presence or absence of peripheral
blood monocytosis. Patients with greater than 30% blasts in the bone
marrow were considered to have acute leukaemia. The term preleukaemia
was deliberately avoided, since many patients with MDS die either of
pancytopenia without evolution to acute leukaemia or of incidental cause.

44. FAB Classification of myelodysplastic syndrome (MDS)
Peripheral blood Bone marrow
Refractory anaemia (RA) Blasts <1% Blasts <5%
Refractory anaemia with
Ring Sideroblast (RARS)
Blasts <1% Blasts <5% Ring
Sideroblasts >15%
of total erythroblast.
Refractory anaemia with
excess of blasts (RAEB)
Blasts <5% Blasts 5—20%
Refractory anaemia with
excess blasts in
transformation (RAEBT)
Blasts > 5% Blasts 20—30% or
Auer rods present.
Chronic myelomonocytic
leukaemia (CMML)
As any of above
with 1.0x109/L
monocytes.
As any of above
with promonocytes

45. • In some case neutropenia or thrombocytopenia is
present without anaemia. These cases are classified as
refractory cytopenia (WHO). Patients are usually
elderly female. Refractory anaemia with ring
sideroblast (>15%) are also known as primary
acquired sideroblastic anaemia.
• Blood film and bone marrow findings –
• See Hoffbrand page-447.

46. Paraproteinaemia (Monoclonal
gammopathy, Plasma cell dyscrasia)
• Proliferation of single clone of immunoglobulin
producing cells which produce a single homogeneous
protein (Monoclonal immunoglobin) which are
functionally abnormal immunoglobulin and during
electrophoresis migrate as a discrete monoclonal band
or spike are known as paraproteinaemia.
• Causes of paraproteinaemia:
• Benign :
• Benign monoclonal gammopathy
• Solitary plasmacytoma
• Chronic cold haemagglutinin disease.

47. • Malignant or uncontrolled proliferation :
• Multiple myeloma
• Waldenstrom’s macroglobulinaemia
• Malignant lymphoma
• Chronic lymphocytic leukaemia
• Primary Amyloidosis.
• Plasma cell leukaemia
• Heavy chain disease.

48. Multiple Myeloma
• It is a disease of plasma cell where sheets of plasmablast
are present in the bone marrow.
• Def : Neoplastic proliferation of monoclonal plasma
cells with infiltration of various tissue especially
skeletal system and production of paraprotein is known
as multiple myeloma.
• Aetiology and Pathogenesis :
• It usually develops in elderly
• Both sexes are equally involved.

49. • Cardinal features of multiple myeloma
• Pathological fracture
• X-ray skull show multiple lytic lesion.
• Urine show Bence Jones Proteinuria.
• Markedly raised ESR.
• Blood film show marked rouleaux formation.
• Diagnosis is confirmed by :
• Bone marrow examination and
• Plasma protein electrophoresis.
• Bone marrow show sheets of Plasmablast
• Plasma protein electrophoresis show M-band.

50. • Pathophysiology :
• Pathological and clinical feature of multiple myeloma
are predominantly due to :
• 1) Tissue infiltration
• 2) Production of large amount of paraprotein.
• 3) Impairment of immunity.
1) Tissue infiltration particularly bone infiltration by
plasma cells leads to destruction of cortical and
medullary bones. This is due to stimulation of
osteoclastic activity by cytokines designated as
osteoclast-activating factor by malignant plasma
cells. This lead to osteoporosis, lytic lesion of bone
and pathological fracture. Increased resorption of
bone results in hypercalcaemia.

51. • 2) Large amounts of paraprotein may cause :
• Raised ESR, Increased rouleaux formation.
• Hyperviscosity
• Interference of platelet function and coagulation
pathway.
• Proteinuria
• Renal failure
• Amyloidosis
• Cryoglobulinaemia.

52. Myeloproliferative disorder
• Myeloproliferative disorder are disorder where there is
uncontrolled proliferation of abnormal progenator cells which are
capable of producing erythroid, myeloid and megakaryocytic
series. The particular type of disorder is determined by the
predominant series into which the cell differentiate. The following
disorder are included in Myeloproliferative disorder :
• Polycythaemia vera
• Essential thrombocythaemia
• Chronic myeloid leukaemia
• Myelofibrosis.
These disorder are grouped together because of their clinical and
morphological similiarities. (1) All display a hyperplastic bone
marrow (2) Haematopoiesis independent of physiologic stimuli (3)
A phase of increased circulating blood cell concentration (4) A
tendency twards the development of marrow fibrosis (5) A
tendency to terminate in acute leukaemia.

53. Polycythaemia
• The term polycythaemia, strictly speaking, implies
elevated levels of all cellular elements of the blood,
although it is usually used when there is elevation of
the red cell count alone or in combination with
elevation of granulocyte or platelet number.
• Polycyhthaemia may be :
• True Polycythaemia
• Relative Polycythaemia
• True Polycyhthaemia may be :
• Primary or polycythaemia vera : When no cause is
known
• Secondary : When cause is known

54. Causes of secondary polycythaemia
• Secondary to tissue hypoxia
• High altitude
• Congenital heart disease
• Chronic pulmonary disease
• Acquired heart disease.
Secondary to inappropriately increased erythropoietin
production.
Non-neoplastic kidney disease : Cysts, Hydronephrosis.
Tumours : Kidney, liver, cerebral haemangioblastoma.
Causes of relative polycythaemia
Dehydration.

55. Polycythaemia Rubra Vera (Primary polycythaemia,
Primary proliferative polycythaemia)
• It is a chronic, progressive and ultimately fatal disease
in which there is excess production of formed elements
of blood by a hyperplastic bone marrow.
• Pathophysiology :
1) The dominant clinical feature is due to overproduction
of red cell. Increase red cell mass cause increase blood
volume. Plasma volume is usually normal.
2) Increase blood viscosity
3) Increase platelet adhesiveness.
Haemorrhagic tendency is probably due to vascular
engorgement due to increase blood volume and defects
in platelet function.

56. • Major and minor criteria for the diagnosis of polycythaemia
vera :
• Major Criteria
• M1 : Increased red cell mass (RCN)>125%
• M2 : No evidence of secondary polycythaemia including arterial
• O2 saturation of >92%.
• M3 : Palpable spleenomegaly.
• Minor Criteria :
• m1 : Thrombocytosis > 4,00,000/µl
• m2 : Leukocytosis > 12,000/µl
• m3 : Leukocyte alkaline phosphatase activity>100
• m4 : Serum B12 (>900 ρg/ml) or unsaturated B12 binding
capacity >1200 ρg/ml
• The diagnosis of polycythaemia vera require the presence of all
three major criteria or the first two major criteria and two minor
criteria.

57. • Clinical features :
• Age : Middle and old age (40 to 80 years).
• Sex : Male > Female.
• Sign and symptoms :
• Most common symptoms are :
Cerebral symptoms : Headache, Dizziness, fullness
in the head.
CVS symptoms : Dyspnoea due to hypoxia.(Increase
blood viscosity causes slowing of circulation with
resultant hypoxia)
Angina due to ischaemia.
Cardiac failure due to volume overload.

58. • Devolopment of red face or blood shot eyes.
• GIT symptoms especially dyspepsia due to vascular
engorgement of alimentary tract.
• Visual disturbance due to engorgement of retinal
veins.
• Haemorrhagic manifestation due to vascular
engorgement and defects in platelet function.
• Sign :
• Red colour of the skin
• Ruddy cyanosis of mucous membrane.
• Conjunctival vessels are injected (Congested).
• Spleenomegaly
• Opthalmoscopy : Engorged tortuous vein in retina.

59. • Blood picture :
• Blood obtained by venepuncture is dark, thick and
clots readily.
• Hb : Raised.
• PCV : Raised
• MCV : Normal or reduced
• MCH : Normal or reduced
• ESR : Very low.
• Blood film : Normocytic Normochromic. There may
be few polychromatic RBC and occasional nucleated
RBC.
• WBC : Usually raised total count.
• Platelets are increased

60. • Other Investigation :
• Leukocyte Alkaline Phosphatase : Raised
• Serum Vit B12 is higher.
• Transcobalamin – Very high.
• Bone marrow :
• Hypercellular marrow with predominance of
erythroid series. Erythropoiesis is normoblastic.
Granulopoiesis is active and maturing to segmented
form. Megakaryocytes increased.
• Bone marrow iron study : No stainable iron
• Iron clearance study : Less than 15 minutes.

61. Difference between primary and secondary
polycythaemia
Primary polycytaemia Secondarypolycythaemia
Cause is not known Cause is known
C/F : Headache,
dizziness, Ruddy
cyanosis, Blood spot
eye.
Sign symptoms of
primary disease.
Bluish cyanosis.
All formed elements of
blood are increased
Only erythrocytosis.

62. Primary polycytaemia Secondarypolycythaemia
Bone marrow :
Hypercellular marrow
with increase in all
series.
Hypercellular marrow
with increase in erythroid
series only.
Bone marrow iron
study.
No stainable iron
Stainable iron is normal
Iron clearance study
Less than 15 minutes
About 16 to 30 minutes.

63. Primary polycytaemia Secondarypolycythaemia
Biochemical Study :
Neutrophil Alkaline
phosphatase activity :
Increased.
Neutrophil Alkaline
phosphatase activity :
Normal
Erythropoietin level :
Normal
Erythropoietin level :
Raised
Gas Analysis :
Po2 normal
Po2 less than normal

64. Myelofibrosis
• The term myelofibrosis is used to describe fibrosis and
collagen formation in the bone marrow. Myelofibrosis
may be classified as Primary and Secondary.
• Primary myelofibrosis : When no cause is known or
myelofibrosis follows in patient with Polycythaemia
vera. Primary myelofibrosis usually accomapanied by
myeloid metaplasia in the spleen and liver.
• Secondary myelofibrosis : When myelofibrosis
develop in association with some well-defined
disorder of marrow or as a result of toxic action of
chemical agents or irradiation. Fibrosis may be seen in
Tuberculosis, Secondary carcinoma, Hodgkin’s
disease, Leukaemia etc. Myeloid metaplasia is very
much less common in Secondary myelofibrosis.

65. Haemostasis
• Normal hemostasis is a tightly regulated processes
that maintain blood in a fluid state in normal vessels,
yet also permit the rapid formation of a hemostatic
clot at the site of a vascular injury. Hemostasis
involve three components: the vascular wall
(particularly the endothelium), platelets, and the
coagulation cascade.

66. • The general sequence of events in hemostasis at a site
of vascular injury :
• After initial injury there is a brief period of arteriolar
vasoconstriction mediated by reflex neurogenic
mechanisms and augmented by the local secretion of
factors such as endothelin (a potent endothelium-
derived vasoconstrictor). The effect is transient, and
bleeding would resume if platelet and coagulation
systems are not activated.
• Endothelial injury exposes highly thrombogenic
subendothelial extracellular matrix (ECM),
facilitating platelet adhesion and activation.

67. • Activation of platelets results in a dramatic shape
change (from small rounded discs to flat plates with
markedly increased surface area), as well as the
release of secretory granules. Within minutes the
secreted products recruit additional platelets
(aggregation) to form a hemostatic plug; this process
is referred to as primary hemostasis
• Tissue factor is also exposed at the site of injury.
Tissue factor is also known as factor III and
thromboplastin. Tissue factor is a membrane-bound
glycoprotein synthesized by endothelial cells. It acts
in conjunction with factor VII as the major extrinsic
pathway of initiator of the coagulation cascade,
eventually culminating in thrombin generation.

68. • Thrombin cleaves circulating fibrinogen into
insoluble fibrin, creating a fibrin meshwork, and also
induces additional platelet recruitment and activation.
This sequence, secondary hemostasis, consolidates
the initial platelet plug.
• Polymerized fibrin and platelet aggregates form a
solid, permanent plug to prevent any further
hemorrhage.

69. • Fate of haemostatic plug
• The platelets in the haemostatic gradually undergo autolysis
and are replaced by fibrin, so that after 24—48 hours the
haemostatic plug has been transformed into a dense fibrin
mass. This fibrin mass is then gradually digested by the
fibrinolytic enzyme system and the defect in the vessel wall
then becomes covered with endothelial cells.
• Extravascular factor :
• Haemostasis is also influenced by extravascular factors,
namely tissue tension and the support of the vessels, which
play an important subsidary role, particularly in venous
bleeding. In tissue with a high tissue tension, the natural tissue
tension together with increased tension caused by mass of
escaped blood, compress these damaged vessels lessens blood
loss. When vessels are contained in loose tissue and are poorly
supported bleeding tends to continue. Thus vessels in nasal
septum, which have a rigid septum in one side and no support
on the other side are particularly liable to bleed.

70. • Vessels in the gastrointestinal mucosa, in the bladder
and in the renal pelvis are not well supported;
bleeding from this sites occur easily after slight
trauma and in disorder of haemostatic mechanism
and can be difficult to control. In other areas where
the tissue tension is low, eg in the subcutaneous tissue
of the scrotum and about the orbit, mild trauma may
result in extensive haemorrhage.

71. Idiopathic (Immune) thrombocytopenic
purpura
• This is a disorder which is characterized by
thrombocytopenia in almost all cases due to antibody
formation(Antiplatelet antibody).
• Female is more common than male.
• Blood picture :
• Reduced platelet count. RBC : Microcytic
• hypochromic.
• Iron deficiency anaemia common.
• Bone marrow : Megakaryocyte increased.

72. Coagulation disorder
• Common congenital coagulation disorder:
• Haemophilia A or classical haemophilia (Factor VIII
deficiency).
• Haemophilia B or christmas disease (Factor IX
deficiency).
• Von Willebrand disease.

73. • Common acquired coagulation disorder:
• Liver disease
• Vitamin K deficiency
• Disseminated intravascular coagulation
• Anticoagulant drugs.

74. • Investigation for Bleeding disorder :
• Bleeding time : 2—7 minutes
• Clotting time : 5—11 minutes
• Prothrombin time : 12—16 seconds
• Activated partial thromboplatin time :30—40 s
• Thrombin time : 15—19 seconds.