Acute Lymphoblastic Leukemia (ALL): Types and Diagnosis

What is acute lymphoblastic leukemia?

Acute lymphoblastic leukemia (ALL) is a fast-growing blood cancer that starts in the disease-fighting lymphocytes. The bone marrow produces too many immature lymphocytes, called lymphoblasts, which crowd out normal blood cells. Diagnosis generally requires at least 20% lymphoblasts in the bone marrow, and the disease can involve the marrow, blood, and organs such as the testicles and central nervous system.

B-cell and T-cell ALL

ALL is divided into two main categories — B-cell ALL and T-cell ALL — each with several subtypes defined by genetic mutations and immunophenotype. Genetic testing is very important to identify the subtype. B-ALL is the most common form and may carry the Philadelphia chromosome, while T-ALL is more common in adolescent males and usually lacks this abnormality.

How ALL is diagnosed

Diagnosis uses bone marrow aspirate and biopsy, flow cytometry to identify cells, and genetic analyses such as FISH, karyotyping, and PCR. A lumbar puncture (spinal tap) removes spinal fluid to check for central nervous system involvement and can deliver chemotherapy directly to the CNS.

Planning treatment

These tests establish the precise ALL subtype and guide a personalized treatment plan. Risk factors are weighed, and stem cell transplantation is considered as part of the strategy — so early transplant evaluation and donor identification are recommended. Combining chemotherapy, targeted therapy, and, when needed, bone marrow transplantation improves outcomes for many patients.

This article is for general information only and is not a substitute for professional medical advice. Always consult a qualified specialist about your individual condition.