<aside> 💡 85% present as leukemia (bone marrow →blood), rest as lymphoma (tissues)

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Neoplasm of lymphoblasts (immature lymphocytes) or lymphoid stem cells (85% pre-B, 15% pre-T).

• FAB classification L1, L2 & L3

Demographics

• Any age, Most common childhood cancer.
  • ~ Age 4 M/F = Pre-B cell origin.
  • ~ Age 18 M = Pre-T cell origin.
• L1 - CD10 +ve (Pre B lymphocytes) - commonest, presents ~4yrs
• Pre-T, rare, males, ~18yrs

Risk Factors

• Child or adolescent age.
• Male gender.
• Down Syndrome.
• Radiation and chemical (i.e. benzene) exposure.
• Viral infections.

Aetiology

• Idiopathic, genetic, viral infections (mutations)