Pediatric Leukemias: Diagnosis

Children and young adults with leukemia have the best outcomes when they begin treatment as soon as possible. At Memorial Sloan Kettering, we diagnose patients with leukemia using a quick and thorough approach.

Knowing as much as possible about your child's leukemic cells is the first step toward determining the most effective course of treatment. We begin by examining the child's blood cells using a complete blood count (CBC) test and a blood smear. This allows us to see if the numbers of red blood cells, white blood cells, and platelets fall within a normal range and to detect any abnormal-looking cells in the circulating blood.

We also take a complete medical history and perform a physical exam, noting anything of significance, such as fever, rash, or bruising; enlarged lymph nodes, liver, or spleen; or a lump where leukemic cells have clumped together. In addition, we draw blood to perform a variety of advanced evaluations — including genetic testing — to determine the characteristics of the leukemic cells. Almost all testing is performed at Memorial Sloan Kettering so that results are available as quickly as possible.

Not every child or young adult with leukemia has an abnormal blood count. Sometimes a blood count will not reveal a leukemia diagnosis, but the doctor's physical examination and study of the blood under a microscope may still suggest that the child has the disease. In these cases, we can detect leukemia by examining cells removed from the bone marrow through an aspiration or a biopsy, or from the spinal fluid through a lumbar puncture, also called a spinal tap. These procedures are performed while the child or young adult is briefly placed under anesthesia to minimize any possible discomfort.

Before treatment begins, doctors study all available test results and physical exam findings to determine which type of leukemia your child has and the extent of the disease. We also determine what is called the risk group, or the risk of the cancer returning after your child is in remission. Remission is achieved when treatment has destroyed nearly all abnormal blood cells and normal blood cell production resumes.

Young patients who come to Memorial Sloan Kettering frequently begin treatment on the same day they are diagnosed. Children and young adults who have a standard risk of the cancer returning after remission will undergo less-intensive treatment to minimize potential side effects. Children at a higher risk of possible relapse will receive more-intensive treatment. These different treatment intensities give both standard- and high-risk children a similar chance of cure.