Leukaemia (acute lymphoblastic)

Question 1

Definition

Answer 1

Malignancy of the bone marrow and blood characterised by the proliferation of lymphoblasts (primitive lymphoid cells)

Question 2

Aetiology

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

o Environmental (radiation, viruses)

o 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

Presenting symptoms (bone marrow failure)

Answer 5

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

Question 6

Presenting symptoms (organ infiltration)

Answer 6

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

Question 7

Signs on physical examination (bone marrow failure)

Answer 7

o Pallor
o Bruising
o Bleeding
o Infection

Question 8

Signs on physical examination (organ infiltration)

Answer 8

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

Question 9

Investigations (blood)

Answer 9

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

· Blood Film
o Abundant lymphoblasts

Question 10

Investigations (other)

Answer 10

· Bone Marrow Aspirate or Trephine Biopsy
o 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