Leukaemia - Acute Lymphoblastic

Question 1

Define

Answer 1

DEFINITION: malignancy of the bone marrow and blood characterised by the proliferation of lymphoblasts (primitive lymphoid cells)

Question 2

Causes

Answer 2

Lymphoblasts undergo malignancy transformation and proliferation

This leads to the replacement of normal marrow elements, leading to bone marrow failure and infiltration into other tissues

Question 3

Risk factors

Answer 3

Environmental (radiation, viruses)

Genetic (Down’s syndrome, Neurofibromatosis type 1, Fanconi’s anaemia, xeroderma pigmentosum)

Question 4

Epidemiology

Answer 4

MOST COMMON malignancy of CHILDHOOD

Peak incidence: 2-5 yrs old

There is a second peak in incidence in the elderly

Annual UK incidence: 1/70,000

Question 5

Symptoms

Answer 5

Symptoms of Bone Marrow Failure:

• Anaemia (fatigue, dyspnoea)
• Bleeding (spontaneous bruising, bleeding gums, menorrhagia)
• Opportunistic infections

Symptoms of Organ Infiltration:

• Tender bones
• Enlarged lymph nodes
• Mediastinal compression
• Meningeal involvement (headache, visual disturbances, nausea)

Question 6

Signs

Answer 6

Signs of Bone Marrow Failure:

• Pallor
• Bruising
• Bleeding
• Infection

Signs of Organ Infiltration:

• Lymphadenopathy
• Hepatosplenomegaly
• Cranial nerve palsies
• Retinal haemorrhage
• Papilloedema on fundoscopy
• Leukaemic infiltration of the anterior chamber of the eye
• Testicular swelling

Question 7

Investigations

Answer 7

Identify appropriate investigations for acute lymphoblastic leukaemia

Bloods

• FBC - normochromic normocytic anaemia, low platelets, variable WCC
• High uric acid
• High LDH
• Clotting screen

Blood Film

• Abundant lymphoblasts

Bone Marrow Aspirate or Trephine Biopsy

• Hypercellular with > 20% lymphoblasts

Immunophenotyping - using antibodies to recognise cell surface antigens

Cytogenetic - karyotyping to look for chromosomal abnormalities or translocations

Cytochemistry

Lumbar Puncture - check for CNS involvement

CXR - may show mediastinal lymphadenopathy, lytic bone lesions

Bone Radiographs - mottled appearance with punched out lesions due to leukaemic infiltration