Because the symptoms of leukemia are nonspecific and the causes are not clearly defined, one's health care professional will carry out a complete history and physical examination and any appropriate tests in order to identify the underlying cause.
- The health care professional will ask many questions about symptoms, current medical situations, medications, medical and surgical history, family history, work history, and habits and lifestyle.
- The physical examination includes a thorough evaluation of all symptoms, not merely lymph nodes and/or possible enlargements of the liver and spleen.
Blood tests: Blood is drawn from a vein in order to check the blood cell counts. In most cases of leukemia, the white blood cell count is abnormal - either very low, or more commonly, very high (although it is not uncommon for the white cell count to be normal in many of the childhood acute lymphocytic leukemias) and the platelet and red cell counts are low. This makes the health care professional consider leukemia as the diagnosis. Other tests are performed to check liver and kidney functions and the possible presence of leukemic cells in the spinal fluid.
Biopsy: Because other conditions may give rise to atypical white cell counts, the only way to confirm the diagnosis of leukemia is via an aspirate and biopsy of the bone marrow.
- Biopsy means to take a small sample of the relevant tissue to check for abnormal cells. In leukemia, a biopsy of the bone marrow must be taken and examined.
- This procedure is usually performed in the medical office, usually by a specialist trained in the treatment of blood disorders, that is, a hematologist or a hematologist-oncologist. The procedure is brief (less than a few minutes) and preceded by a local injection for anesthesia.
- Samples of both liquid (aspirate) and solid bone marrow (biopsy) are taken, usually from a hip bone.
- The bone marrow is examined under a microscope, where the presence of leukemic cells confirms the suspected diagnosis.
Genetic and molecular studies: The detailed subtypes of the structures of the leukemia cells as well as the chromosomes of the abnormal cells are examined to look for irregularities. This helps in classifying the various types of leukemia.
Lumbar puncture (spinal tap): Because the collection of leukemia cells in the central nervous system can affect essential mental processes and processes controlled by the nervous system, it is extremely important to know whether the fluid surrounding the brain and spinal cord (cerebrospinal fluid) is affected.
- This procedure is referred to as a lumbar puncture or spinal tap and is usually carried out by the blood specialist in the office. After the procedure, the person needs to lie flat for 1 to 2 hours.
- A small amount of the fluid is removed from the area around the spinal cord by inserting a hollow needle in the back at around the waist level. The needle is inserted in between the bones in the spine following a small injection into the skin over the injection site in order to minimize discomfort.
- The fluid is examined for the presence of leukemia cells.
Lymph node excision: If the lymph nodes are enlarged, a node may require a biopsy if the bone marrow is difficult to interpret for some obscure reason. This is exceedingly uncommon.
Chest X-ray: A chest X-ray is frequently taken to look for signs of infection or lymph node involvement by leukemia.
Staging is the way cancers are classified. Staging indicates the size or extent of spread of the cancer, the degree to which other parts of the body are affected, and other important details. In general, leukemias are classified rather than staged in order to determine the most appropriate therapy.
All leukemias are classified according to their genotypes, or their unique chromosomal arrangements, which also enables the physicians to determine risk factors. Today testing of surface markers on leukemia cells by flow cytometry also helps to classify the type of leukemia present.
In addiction, chronic myelogenous leukemia is classified by phase. The three phases are chronic phase, accelerated phase, and blast phase (or "blast crisis") and are defined by the number of blasts (immature leukemia cells) in the blood and bone marrow.
Chronic lymphocytic leukemia is classified by two different staging systems, both based on the types of blood cells and the parts of the body affected by the leukemia.