Acute leukaemias

Clinical features:

The symptoms of acute leukaemia are a consequence of bone marrow failure:

• Symptoms of anaemia:
• Tiredness
• Weakness
• Exertional dyspnoea
• Repeated infections

There may be few or no abnormal physical signs; but patients often have:

• Signs of anaemia
• Bruises, petechial haemorrhages, purpura, fundal haemorrhages
• Signs of infection
• Occasionally, lymph node enlargement and/or hepatosplenomegaly

Investigations:

• FBC:
• Low Hb
• WCC (may be raised, normal or low)
• Thrombocytopenia

Peripheral blood film:

• Shows characteristic leukaemic blast cells

Bone marrow aspirate:

• Shows increased cellularity with abnormal lymphoid or myeloid blast cells

General principles of management:

Before starting treatment, the following points must be considered:

• Correction of anaemia and thrombocytopenia with the administration of blood and platelets
• Infection should be treated with IV antibiotics
• Leukaemic blast cells can infiltrate the brain and lungs – resulting in coma and respiratory failure respectively. If the blast cell count in the peripheral blood is very high (>100x10⁹/L) the patient may need leucophoresis:
• Blood is collected from a vein and centrifuged so as to remove leukaemic cells, and the RBCs and plasma are then returned to the patient via another vein
• Leucophoresis can be life-saving

• In certain types of leukaemia, where the rate of cell division is very fast (e.g. B-cell and T-cell ALL), patients may develop a ‘tumour lysis’ syndrome when chemotherapy is given:
• Hypercalcaemia
• Hyperphosphataemia
• Hyperkalaemia
• All resulting from a high rate of cellular breakdown
• Is potentially life-threatening and difficult to treat once it has occurred

Classification:

Leukaemia can be divided on the basis of the speed of evolution of the disease into acute or chronic. Each of these is then further subdivided into myeloid or lymphoid, according to the cell type involved. Hence the terms:

• Acute myelogenous leukaemia (AML)
• Acute lymphoblastic leukaemia (ALL)
• Chronic myeloid leukaemia (CML)
• Chronic lymphocytic leukaemia (CLL)