Acute lymphoblastic leukemia

Acute lymphoblastic leukaemia (ALL) also referred to as acute lymphocytic leukaemia, is a primary neoplasm of the bone marrow. (1,2,3)

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

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). In Philadelphia chromosome-positive ALL patients:

• usually presents with higher white blood cell and blast counts
• 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)

Survival rates for ALL have improved dramatically since the 1980s, with a current five-year overall survival rate estimated at greater than 85 per cent (4).

References:

1. Alaggio R, Amador C, Anagnostopoulos I, et al. The 5th edition of the World Health Organization classification of haematolymphoid tumours: lymphoid neoplasms. Leukemia. 2022 Jul;36(7):1720-48.
2. National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: acute lymphoblastic leukemia [internet publication].
3. Terwilliger T, Abdul-Hay M. Acute lymphoblastic leukemia: a comprehensive review and 2017 update. Blood Cancer J. 2017 Jun 30;7(6):e577.
4. Puckett Y, Chan O. Acute Lymphocytic Leukemia. [Updated 2023 Aug 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan.