Acute Lymphocytic Leukemia
DescriptionAn in-depth report on the causes, diagnosis, treatment, and prevention of leukemia.
Alternative NamesAcute Lymphoblastic (or Lymphocytic) Leukemia
Laboratory tests provide the basis for diagnosing ALL.
Flow cytometry is an important diagnostic technique in leukemia that uses complex fluids, laser optics, and computers. It is most often used to count blood cells but it can also determine the components and structural features of cells. It can process thousands of cells in seconds and take measurements of a single cell. Advanced techniques using flow cytometry employ fluorescent light that is scattered by cells and revealed by lasers. The features of the scattered light allow experts to detect many characteristics of the cells. It is important in leukemia for diagnosing patients, for providing information on their prognosis, and for identifying residual disease after treatments.
Complete Blood Cell Count
A complete blood cell count is the first step in diagnosing ALL. This test will often show various findings, including the following:
Blood tests do not always detect leukemia, and about 10% of patients with ALL have a normal blood cell count.
Bone Marrow Biopsy
If the results of the blood tests are abnormal or the physician suspects leukemia despite normal cell counts, a bone marrow aspiration and biopsy are the next steps.
Normal bone marrow contains 5% or less blast cells (the immature cells that ordinarily develop into healthy blood cells). In leukemia, abnormal blasts constitute between 30% and 100% of the marrow.
If bone marrow examination confirms ALL, a spinal tap may be performed, which uses a needle inserted in to the spinal canal. The patient feels some pressure and usually must lie flat for about an hour afterward to prevent severe headache. This can be difficult, particularly for children, so parents should plan reading or other quit activities that will divert the child during that time. Parents should also be certain that the professional administering this test is highly experienced.
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, leukemic cells are not found in the cerebrospinal fluid.