Diagnosis of Chronic Lymphocytic Leukemia

Many tests are performed to find or diagnose cancer. They also do tests to see if cancer has spread to another part of the body from where it began. If this happens, it is called metastasis. For instance, imaging tests can represent if cancer has spread. Imaging tests show pictures of the body from the inside. Doctors can also do tests to learn which treatments would work best.

A biopsy is the sure short way for the doctor to know if an area of the body has cancer for most types of cancer. In a biopsy, the doctor takes a small tissue sample for testing in a laboratory. The doctor may suggest other tests if a biopsy cannot help diagnose.

The doctor may consider given factors when choosing a diagnostic test:

  • Your signs and symptoms
  • The age and general health status
  • The type of cancer suspected
  • The result of earlier medical tests

The below-mentioned tests may be used to diagnose CLL-

Blood tests

Diagnosing CLL usually starts with a blood test called a complete blood count (CBC). A CBC measures the count of different cells in a person’s blood sample. If the blood contains many white blood cells, a person may have CLL. This result is a high white blood cell (WBC) count. The doctor also uses the blood test to determine which white blood cells are increased. The CBC also measures platelets and red blood cells. People having CLL may have low levels of these cells. Low levels of red blood cells are called anaemia. A low platelet count is called thrombocytopenia.

Blood tests can also collect leukemia cells for testing for certain genetic markers that can predict the risk that the disease will worsen.

Flow cytometry and cytochemistry

In these tests, chemicals or dyes are applied to the leukemia cells in the laboratory. These chemicals and dyes provide information about leukemia and its subtype. CLL cells have distinctive markers, known as cell surface proteins, outside the cell. The pattern of these markers is known as the immunophenotype. These tests are used to differentiate CLL from other leukemia involving lymphocytes. Both tests can be performed from a blood sample. Flow cytometry, also known as immunophenotyping, is the most crucial test to confirm CLL diagnosis.

Genomic and molecular testing

Your doctor may recommend running laboratory tests to identify specific genes, proteins, and other factors involved in leukemia. Because CLL cells divide slowly, looking at the chromosomes is often less helpful than testing particular genetic mutations or changes. Fluorescence in situ hybridization (FISH) assays and other genetic tests, like polymerase chain reaction (PCR), is used to find genetic changes. Some of the genetic changes that happen in CLL include –

  • An extra copy of chromosome 12 (trisomy)
  • The deletion of the long arm of chromosome 13 [del(13q)] is found in about half of patients.
  • SF3B1 mutations
  • del(11q)
  • del(17p)
  • IGVH, which can be important whether it is changed or unchanged
  • TP53 abnormalities
  • NOTCH1 mutations
  • MYD88 mutations

Genetic and molecular testing can determine how quickly the disease will progress and help determine your treatment options. For instance, people with del(17p) are more likely to have difficult-to-treat leukemia, and some treatments can work better than others for these patients.

Imaging tests

CLL is generally found in many body parts, even if the disease has been diagnosed early. Imaging tests are rarely required to diagnose CLL. They are sometimes used before the treatment to find all body parts affected by CLL or determine whether particular symptoms may be related to CLL. Imaging tests may also be used to see how well the treatment works.

An x-ray is a way to create an image of the structures inside of the body, using a small amount of radiation. It may show if leukemia is growing in lymph nodes in the chest.

A CT scan takes pictures of the body from inside using x-rays taken from different angles. A computer then combines these pictures into a detailed, 3-dimensional image showing abnormalities or tumours. A CT scan can be used to determine the tumour’s size. Occasionally, a specific dye called a contrast medium is given before the scan to provide detail on the image. This dye can be delivered into a patient’s vein or provided as a pill or liquid to swallow. There is a risk of kidney problems from this contrast medium; talk to the doctor about this before the test.

CT scans can also help determine if CLL is in other organs, such as the spleen. A CT scan is generally not needed if diagnosed with no symptoms. It is usually done only before treatment and at the end of treatment when required.

Bone marrow aspiration and biopsy

CLL is typically diagnosed with blood tests because the cancerous cells are found in the blood. A bone marrow biopsy is usually not required to diagnose CLL, but it may be done before beginning treatment. A bone marrow aspiration and biopsy may help determine a prognosis for a few patients, which is the chance of recovery. It may also provide more information about why other blood tests are abnormal. A bone marrow aspiration and biopsy is similar and often done simultaneously to evaluate the bone marrow, the fatty, spongy tissue found inside larger bones.

Bone marrow has both a liquid and a solid part. A bone marrow aspiration takes a sample of the fluid using a needle. A bone marrow biopsy removes a small quantity of solid tissue using a needle. A pathologist then reviews the samples in a lab. Pelvic bone located by the hip is a common site for bone marrow aspiration and biopsy. Doctors generally give a medication called “anaesthesia” beforehand to numb the area. Anaesthesia is a medication that blocks the awareness of pain.