Acute Lymphocytic Leukemia - Complications

(Page 2)

A sample of cerebrospinal fluid with leukemia cells is a sign that the disease has spread to the central nervous system. In most cases of childhood ALL, leukemia cells are not found in the cerebrospinal fluid.

Tests Performed after Diagnosis

Once a diagnosis of leukemia has been made, further tests are performed on the bone marrow cells:

• Cytochemistry, flow cytometry, immunocytochemistry, and immunophenotyping tests are used to to identify and classify specific types of leukemia. For example, cytochemistry distinguishes lymphocytic leukemia cells from myeloid leukemia cells. Immunophenotyping shows if ALL cells are T cells or B cells based on the antigen located on the surface of the cell.
• Cytogenetics and fluorescent in situ hybridization (FISH) are used for genetic analysis. Cytogenetic testing can detect translocations (such as Philadelphia chromosome) and other genetic abnormalities. FISH is used to identify specific changes within chromosomes. Genetic variations may help determine response to treatment.

Cell Classification

The results of cytogenetic, flow cytometry, immunophenotyping, and other tests can help provide information on types and subtypes of ALL cells. The particular subtype of cell can aid in determining prognosis and treatment.

An older classification system called the French-American-British (FAB) classification grouped ALL into L1, L2, and L3 subtypes. A newer classification system classifies ALL B cells or T cells based on their stage of maturity.

B-Cell ALL Subtype Classification:

• Early Pre-B
• Common ALL
• Pre-B ALL
• Mature B-cell ALL (Also called Burkitt leukemia)

T-Cell ALL Subtype Classification:

• Pre-T ALL
• Mature T-cell ALL

Review Date: 01/27/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).