Types of Acute Lymphocytic Leukemia

Acute Lymphocytic Leukemia (ALL) is leukemia that affects lymphocytes, a type of white blood cell. It is not a single disease, but a group of related diseases. In the past, doctors divided ALL into the following three subtypes, based mainly on how the leukemia cells looked under the microscope:

• L1. Most common in children

• L2. Most common in adults

• L3. Most aggressive type; also called Burkitt-type leukemia

Newer lab tests�now allow�doctors to divide ALL into more specific classifications, based on the type of lymphocyte the disease starts in and how mature the cells are.

• Early Pre-B ALL

• Common ALL

• Pre-B ALL

• Mature B-cell ALL (Burkitt-type leukemia)

• Pre-T ALL

• Mature T-cell ALL