Diagnosis of Childhood Acute Lymphoblastic Leukemia

Executive Summary

Several diagnostic tests are conducted to determine childhood acute lymphoblastic leukemia. The main procedures used to diagnose childhood acute lymphoblastic leukemia are the medical history of the patient, complete blood cell count, physical examination, and bone marrow aspiration. The common diagnostic tests for childhood acute lymphoblastic leukemia include blood tests, bone marrow aspiration and biopsy, chromosome and molecular genetic tests, immunophenotyping, and lumbar puncture (spinal tap).

Diagnosis of Childhood Acute lymphoblastic Leukemia

It is necessary to perform several tests to find or diagnose leukemia. Some of these tests are to check whether cancer has spread to another part of the body from where it began. If this happens, it is called metastasis.

The medical history of a patient, complete blood cell count, physical examination, and bone marrow aspiration are the main procedures to diagnose ALL or rule out other medical conditions ^​1​–

Blood tests

A CBC provides a count of each type of cell in the blood. The blood count may also show abnormal leukaemia cells. The blood count is abnormal for nearly all children with ALL when diagnosed. A blood chemistry test provides information about the kidney and liver function and other measures, such as salt levels.

Bone marrow aspiration and biopsy

These two procedures are similar and often done simultaneously to evaluate the bone marrow, which is the fatty, spongy tissue found inside larger bones. Bone marrow has both a liquid and a solid part. A bone marrow aspiration removes 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. More substantial types of anaesthesia are also available to lessen the pain.

A bone marrow aspiration is suggested if the blood test shows unusual blood counts or immature cells or if the doctor suspects a child may have leukaemia ^​2​. From this test, the doctor can determine whether the child has leukaemia and, if so, what type of leukaemia it is. The doctor or health care team member will collect more than one sample of bone marrow simultaneously for further tests, such as chromosome and molecular genetic tests and immunophenotyping. These additional tests are essential to plan the child’s treatment(s).

Lumbar puncture (spinal tap)

A lumbar puncture can determine if leukaemia has spread to the cerebral spinal fluid. Cerebrospinal fluid is the fluid that flows around the brain and the spinal cord. During the lumbar puncture, a needle is used to take a sample of the Cerebrospinal fluid to look for leukaemia cells.

Doctors may give an anaesthetic to numb the lower back before the procedure or use anaesthesia to block awareness of the pain. Knowing whether or not there is leukaemia in the central nervous system helps doctors choose the most appropriate treatment. All children having ALL receive medicine to treat or prevent leukaemia of the CNS at the same time as lumbar puncture at specific times during treatment.

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