May be defined abnormal proliferation of haemopoietic cells causes progressively increasing  infiltration of bone marrow and certain forms lymphatic tissues are involved. Neoplastic cells are usually present in the peripheral blood.

Causes:

1.Chromosomal abnormality - most common   cause. e.g.  Philadelphia Chromosome in CML.

2.Ionizing radiation-e.g.X-ray, Radiotherapy.

3. Chemical agents- e.g.  Benzene.

4. Virus- e.g. HTLV-1.

Classification

A)According to clinical course:-

i)Acute Leukaemia.

ii)Chronic Leukaemia.

B) According to  Cell line involved:-

i)Myeloid Leukaemia.

ii)Lymphoid Leukaemia.

 FAB Classification of Acute Leukaemia

AML- M1=    Myeloblastic Leukaemia without maturation.

M2=   Myeloblastic Leukaemia with                     maturation

 M3=   Hypergranular promyelocytic                        Leukaemia

 M4=   Myelomonocytic Leukaemia

 M5= Monocytic Leukaemia

 M6= Erythroleukaemia

 M7= Megakarryoblastic leukaemia.

ALL-

-    Homogenous small lymphoblast.

-    Heterogenous lymphoblast.

-    Homogenous large lymphoblast.

Clinical Features

Common-    Anaemia, Fever, Malaise,           Haemorrhage, Bruise.

Less Common- Pain in bone & Joint

     -Superficial Lymphnode                enlargement

     -Gum hypertrophy.

                       -URTI

* Acute leukaemia in children usually lymphoblastic type and in adult myeloblastic type.

Laboratory Diagnosis

1.1.Blood Picture

i)Routine – Hb%-  Reduced (Moderate to      severe anaemia)

     WBC-  Total count ranges        between subnormal to      markedly elevated.

     ESR-   Increased.

2. PBF –

i)RBC – Moderately anisocytic & poikilocytic. Reticulocyte increased upto 5% and small number of nucleated cells are present.

ii) WBC – Predominant cells are blast cells (Myeloblast/Lymphoblast)

iii)Platelets – Thrombocytopenia often below 50000/cumm of blood.

3. Bone Marrow

Cellularity – Hypercellular

M:E ratio- Increased

Erythropoiesis- Reduced

Leucopoiesis - Markedly Increased, mostly blast form.

Megakarryocytes- Reduced.

4. Special investigations

(a)Cytochemical Stain:

i)Myeloperoxidase and Sudan Black B- Positive is myeloid & negative in lymphoid series.

ii)    PAS (periodic Acid Schiff) stain- Positive in lymphoid series and erythroblast.

iii) Acid phosphatase – Positive  in ALL.

b)     Enzymes:-

i)Serum lysozyme- Very high in M4, M5.

C)     Cell surface marker- Antigen and recepter present on the leukaemic cells. Helpful the diagnosis of ALL 

Chronic lymphocytic leukemia:http://chroniclymphocyticleukemia.blogspot.com/

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