Acute lymphoid leukaemia

Big picture

Acute lymphoid leukaemia, more commonly called acute lymphoblastic leukaemia (ALL), is an aggressive malignant proliferation of immature lymphoid precursor cells. The key exam idea is:

lymphoblast accumulation → bone marrow failure + lymphoid/extramedullary infiltration + risk of central nervous system and testicular disease.

Think of ALL in a patient with acute constitutional symptoms, infections, bruising/bleeding, anemia symptoms, bone pain, lymphadenopathy/hepatosplenomegaly, and sometimes mediastinal mass or neurological symptoms. The diagnosis is confirmed by bone marrow examination and flow cytometry, and treatment is urgent, multi-phase, and always includes central nervous system prophylaxis.

The hematology textbook describes ALL as a clonal malignant disorder of lymphoid progenitor cells that infiltrates bone marrow and lymphoid organs, can spread through blood, and may involve meninges and testes. It accounts for 20–30% of acute leukemias in adults, with B-cell ALL more common than T-cell ALL.

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