Acute lymphoblastic leukaemia

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)

Reference:

• (1) Faderl  SH, Kantarjian  HM, Estey EH. Hematologic Malignancies: Acute Leukemias
• (2) National Cancer Institute at the National Institutes of Health. General Information About Adult Acute Lymphoblastic Lekemia (ALL)
• (3) Faderl S et al. Adult acute lymphoblastic leukemia: concepts and strategies. Cancer. 2010;116(5):1165-76.
• (4) Fielding AK. Current treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia. Haematologica. 2010;95(1):8-12.