1. Leukemia
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Leukemia is a disease characterized by the progressive
overproduction of WBC which usually appear in the
circulating blood in an immature form.
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It accounts 8% of all human cancers & is common
malignancy in children & young adults.
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Proliferation takes place in the bone marrow and in
certain forms, the lymphoid tissues
2. Etiology –
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Genetic Factors :
- Seen where there is a presence of congenital
disorders such as Down’s, Bloom’s, Kleinfelters
and Wiskott Aldrich Syndromes
—
Environmental
a) Ionising
Hiroshima and
Factors :
radiation (increased incidence in
Nagasaki)
b) Chemical Carcinogens
Benzene & Formaldehyde)
c) Drugs
(Alkylating agents –
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Infection-EBV, HTLV-1
3. Pathogenesis –
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Arises following malignant transformation of a single
clone of cells belonging to myeloid or lymphoid series
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Acute leukemia :
- Defect in maturation beyond the myeloblast
level in AML and lymphoblast in ALL
—
Cells proliferate in the bone marrow and spread to
other tissues
4. —
Philapdelphia Chromosome –
- Thought to be a partial deletion of the long arm
of chromosome 22
- Now recognized to be the translocation of
chromosomal material from chromosome 22 to
chromosome 9
5.
6. Classification:
—
Acute lymphocytic (lymphoblastic) leukemia
(ALL)
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Chronic lymphocytic leukemia (CLL)
Both involve immature lymphocytes and their
progenitors in the bone marrow, the spleen, lymph
nodes, CNS, and other tissue
—
Acute myelogenous (myeloblastic) leukemia
(AML)
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Chronic myelogenous leukemia (CML)
Both involve the pluri-potent myeloid stem cells in
bone marrow and interfere with the maturation of all
blood cells
9. Acute Leukemia
—
It is characterized by neoplastic proliferation of large
number of abnormal immature leukocytes in the
marrow that infiltrate the lymph nodes,liver,spleen &
eventually all body systems.
—
In addition to this, production of other blood cells
inhibited.
are
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Clinical manifestations are divided into 2 groups
- Due to bone marrow failure
- Due to Organ infiltration
10. Bone Marrow Failure :
a. Anemia ( pallor, lethargy, dyspnoea )
b. Bleeding manifestations ( Petechiae, bleeding gums )
Infections
c.
d. Fever
11. Organ Infiltration :
Pain and tenderness { bone infarcts by leukemic
cells }
Lymphadenopathy and enlargement of tonsils
Splenomegaly
Hepatomegaly
Gum Hypertrophy
Chloroma {Localised tumour forming mass
occuring in the skin or orbit due to local
infiltration of the tissues}
Meningeal involvement
a.
b.
c.
d.
e.
f.
g.
13. Bone marrow examination :
- Cellularity : The bone marrow is hypercellular
but sometimes a blood tap or dry tap occurs
- Leukemic Cells : Tightly packed with blast cells
- Erythropoiesis : Reduced
- Megakaryocytes : Reduced or absent
14. Chronic Leukemia
—
In contrast to acute leukemia, chronic leukemia
develops so insidiously that the disease
months or even several years.
may be for
—
Occurs more in males of middle age.
—
Two types :
a. Chronic Myeloid leukemia
b. Chronic Lymphocytic Leukemia
15. Clinical features:
Fever, chills, night sweatsand other f lu-like
symptoms
Weakness and fatigue
Neurological symptoms (headaches)
Enlarged liver and spleen
Frequent infection
Bone pain
Joint pain
Dizziness
Nausea
Swollen tonsils
Diarrhea
Paleness
Malaise
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—Unintentional weight loss
16. Chronic Myeloid Leukemia :
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Comprises about 20% of leukemia
incidence in 3-4th decades of life
and has its peak
—
Both sexes equally affected
18. Bone Marrow Examination :
a. Cellularity : Hypercellularity with total or partial
replacement of fat spaces
b. Myeloid Cells : Predominate in the bone marrow
Erythropoiesis : Normoblastic but presence
reduction
of
c.
d. Megakaryocytes : Smaller in size
Cytogenetics show the presence of philadelphia
chromosome
19. Chronic Lymphocytic Leukemia :
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Constitutes about 25% of all leukemias
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Disease of the elderly with male predeliction
21. Oral manifestation:
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Gingival hyperplasia with bleeding.
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Gingival tissue becomes swollen & edematous due
leukemic cell infiltration.
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Ecchymosis and hematoma formation in the oral
cavity.
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Multiple larger irregular ulcers develop in the oral
mucosa.
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Oral infections
to
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Rapid loosening of teeth due to necrosis of the PDL.
22. Laboratory investigation:
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WBC total count may be either normal or abnormally
or extremely high.
low
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DC of WBC may reveal that one type of leukocyte
overwhelmingly predominant.
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The platelet count & Hb levels are usually low.
is
Bone marrow aspiration:
—
Bone marrow aspiration reveals an increase in the no.
bone marrow cells with an increase in the leukocyte
series.
of
