Last reviewed 05/2019

Acute lymphoblastic leukaemia (ALL) also referred to as acute lymphocytic leukaemia, is a primary neoplasm of the bone marrow.

  • the malignant cells are the lymphocyte precursor cells (immature lymphoid blast cells - lymphoblasts) (1)
  • there is accumulation of lymphoblasts (in the marrow or various extramedullary sites) and also frequent suppression of normal haematopoiesis (2)
  • both B-cell and T-cell lymphoblasts may be responsible for ALL  (1)
  • it is primarily a disease of children and young adults but can occur at any age (2)

The Philadelphia chromosome (Ph1) is seen in around 20% of adults and in a small percentage children with ALL (when compared to acute myeloid leukaemia where Ph1 occurs in only 1% to 2% of patients) (2). In Philadelphia chromosome positive ALL patients:

  • usually presents with higher white blood cell and blast counts (3)
  • children and adults who are sufficiently fit and have a well-matched donor, the most appropriate therapy is myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) (4)