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Acute Lymphoblastic Leukemia (ALL)

What is acute lymphoblastic leukemia?

Graphic showing the blood forming process and how it results in blast cells. The graphic begins with a blood stem cell. To the left, it branches off into myeloid stem cell, which branches into platelets, red blood cells, myeloblast, and monoblast. The myeloblast changes into white blood cells (also called granulocytes) and the monoblast changes into a monocyte. The right branch of blood stem cell goes to lymphoid stem cell, which branches into lymphoblasts (which changes into white blood cells) and blast cells.

Acute lymphoblastic leukemia affects white blood cells called lymphocytes.

Acute lymphoblastic leukemia (ALL) is a cancer of the blood and bone marrow. It is the most common form of childhood cancer.

In leukemia, cancer cells grow rapidly in the bone marrow. When this happens, healthy blood cells — white blood cells, red blood cells, and platelets — cannot do their jobs correctly.

ALL affects white blood cells called lymphocytes. These cells fight infection and help protect the body against disease.

There are 2 types of lymphocytes: B lymphocytes and T lymphocytes. ALL may arise from either type of lymphocyte. Cases of ALL are known as either B cell or T cell ALL. B cell ALL is more common.

About 3,000 children and teens are found to have ALL each year in the United States.

ALL occurs most often in children ages 2–5. It is also found in older children and teens.

ALL in infants is rare. The U.S. sees about 90 cases of ALL in children younger than 1 each year.

Chemotherapy is the most common treatment for ALL. The overall cure rate is about 90% in the U.S.

Research spotlight

Recent discoveries may shed new light on why some childhood leukemias resist treatment.

Read the blog post.

Symptoms of acute lymphoblastic leukemia

Acute leukemia means symptoms get worse quickly. Children may need medical attention right away.

The most common signs and symptoms of ALL are:

  • Pain or fullness below the ribs (enlarged liver and/or spleen)
  • Lumps in the neck, underarm, stomach, or groin
  • Fever
  • Fatigue
  • Easy bruising and bleeding that is hard to stop
  • Pale skin
  • Bone or joint pain
  • Frequent infections
  • Tiny, flat, dark red skin spots (petechiae)
  • Loss of appetite
  • Shortness of breath

Risk factors for acute lymphoblastic leukemia

Most cases of ALL have no known cause.

Certain inherited syndromes are linked to an increased risk of ALL:

  • Down syndrome
  • Neurofibromatosis type 1
  • Bloom syndrome
  • Ataxia-telangiectasia
  • Li-Fraumeni syndrome
  • Certain forms of Fanconi anemia
  • Constitutional mismatch repair deficiency
  • Diamond-Blackfan anemia
  • Familial PAX5 syndrome
  • Familial ETV6 syndrome
  • Familial SH2B3 syndrome

Diagnosis of acute lymphoblastic leukemia 

Illustration of two histology slides side by side highlights the difference between normal bloody cells and blood cells in newly diagnosed ALL.

Children with leukemia usually have a high number of white blood cells in their blood.

Doctors may suspect leukemia after:

  • Doing a physical exam
  • Taking a health history
  • Looking at the results of blood tests

Children with leukemia usually have a high number of white blood cells in their blood.

Physical exam and health history

During the exam and history, the provider will:

  • Check general signs of health, including signs of disease, such as lumps or other unusual symptoms.
  • Examine the eyes, mouth, skin, and ears. The provider will feel the belly for signs of an enlarged spleen or liver. In boys, the provider may also examine the testes.
  • Ask about other health conditions, including illnesses that relatives such as parents, siblings, and grandparents have had. The provider is looking for inherited conditions that may increase cancer risk.

Blood and bone marrow tests

Blood and bone marrow tests are used to diagnose ALL.

A provider will draw blood to run tests. These tests include:

  • Complete blood count – This test checks the counts of different types of blood cells. In ALL, the blood may have too many white blood cells. Many of these cells will be cancer cells.
  • Blood chemistry studies – This test checks the amounts of certain substances in the blood. An unusual level (either higher or lower than normal) can be a sign of disease.
  • Liver function tests
  • Coagulation test – This test measures the blood’s ability to clot.

Bone marrow aspiration and biopsy are 2 tests that will confirm a diagnosis of cancer. Patients usually have these procedures at the same time. They will either be sedated or receive pain medicine.

Tests after ALL diagnosis

If leukemia is found, the care team will run more tests.

These include lab tests to identify specific genes, proteins, and other factors involved in the leukemia.

This is important because cancer is caused by mistakes (mutations) in the cell’s genes. Identifying these mistakes may help diagnose the specific subtype of leukemia.

Doctors use these details to choose treatment options tailored to your child’s case.

The care team also will run tests to find out if cancer is in other parts of the body:

Lumbar puncture

A lumbar puncture will show if leukemia has spread to the brain and spinal cord. The test is also called an LP or spinal tap.

Patients may get chemotherapy at the same time this is done. This is called prophylactic intrathecal chemotherapy. It is given to prevent ALL from spreading to the cerebrospinal fluid.

Chest x-ray

A chest x-ray will show if leukemia cells have formed a mass in the middle of the chest.

Other imaging tests and laboratory tests

Other imaging studies and laboratory tests may be used if patients have certain signs and symptoms.

A female patient of childbearing age may have a pregnancy test.

A male patient may have an ultrasound to check for testicle involvement. This is rare in ALL. It happens in 1–2% of males.

Fertility counseling

The care team may discuss fertility with you and/or your child. Read more about options for males and females.

Treatment of acute lymphoblastic leukemia

Central venous device

Patients will have a surgical procedure to get a central venous access device. This device reduces the need for needle sticks. It allows patients to have blood drawn for lab tests and get intravenous (IV) medicines, fluids, blood products, and nutrition.


Chemotherapy is the main treatment for childhood ALL. It involves several medicines and takes 2–3 years to complete. It is divided into 3 phases:

Risk group

Doctors can tailor treatments to patients based on their risk group.

Risk group refers to the chance that the cancer will not respond to treatment (refractory) or will return (relapse). There are treatment options for relapsed or refractory ALL.

Risk groups include low, standard, high, and very high.

The method of chemotherapy and types of medicine depend on the child’s risk group. For example, children and teens with high-risk leukemia receive more anticancer drugs and/or higher doses than children with low risk ALL.

Risk groups are determined by:

  • Whether the cancer began in B-lymphocytes or T-lymphocytes: B-cell ALL is considered lower-risk than T-cell ALL.
  • Age: Children ages 1–9 with B-cell ALL are generally considered low-or standard-risk. Children younger than 1 and children 10 or older are considered high-risk patients. (This age cut-off may vary among treatment centers.)
  • White blood cell count at diagnosis: Children with a count below 50,000 are considered low-risk.
  • Certain changes in the chromosomes or genes
  • Whether leukemia cells are found in the cerebrospinal fluid (CSF) at the time of diagnosis: If cells have spread to the CSF, the case is treated with more intrathecal therapy.
  • Whether testis is involved by leukemia cells in boys
  • Minimal residual disease as described below. This is an important risk factor.

Minimal residual disease and ALL

Minimal residual disease (MRD) is a term used when there are so few leukemia cells in the bone marrow that they cannot be seen under a microscope.

Highly sensitive tests can detect 1 leukemia cell in 10,000–1 million normal cells in the bone marrow.

Children who have positive MRD (more than 1 cell in 10,000) after induction therapy are at the greatest risk of relapse. The timing of MRD measurement varies depending on the center.

Side effects of acute lymphoblastic leukemia treatment

Side effects are hard to predict. They depend on the medicine and how a person reacts to it. Different people can have different reactions to the same medicine.

Side effects can happen during any phase of ALL treatment. The first weeks of treatment are the most likely to produce serious side effects. There are treatments for these side effects.

Side effects may include:

Prognosis of acute lymphoblastic leukemia

About 98% of children with ALL in the United States go into remission within weeks after starting treatment.

More than 90% of children with ALL in the U.S. can be cured. Patients are considered cured after about 5 years in remission.

Survival rates for ALL patients in low-risk groups can be more than 95%.

If patients have a form of ALL that does not respond to treatment (refractory) or comes back after treatment (relapsed), the medical team will discuss treatment options.

Support for patients with acute lymphoblastic leukemia treatment

Patients may have to miss some school during treatment. The treatment center, school, parents, and student can work together to help the student keep up with school as much as possible.

Late effects of acute lymphoblastic leukemia treatment

Some ALL patients may have late effects. A late effect is a health problem that occurs months or years after treatment has ended.

Cancer patients should continue to be followed by their treatment center care team and/or a primary care provider after cancer treatment. Late effects can often be treated or, in some cases, prevented.

Different treatments may have different late effects. Not all patients will have late effects. Patients who had the exact same treatment may experience different late effects.

ALL patients may be at risk for:

Questions to ask about acute lymphoblastic leukemia

  • What are our treatment options? 
  • What are the possible side effects of each treatment? 
  • What can be done to manage side effects? 
  • Will my child need to be in the hospital for treatment? 
  • Where is the treatment available? Is it close to home or will we have to travel? 
  • Will the treatment affect my child’s ability to have children in the future? What options exist to preserve fertility?

Key points about acute lymphoblastic leukemia

  • Acute lymphoblastic leukemia (ALL) is a cancer of the blood and bone marrow. It is the most common form of pediatric cancer.
  • Bone marrow tests is usually required to diagnose ALL in most of the patients.
  • Chemotherapy is the most common ALL treatment. Treatment takes 2½–3 years.
  • The 5-year survival rate for childhood AML is more than 90% in the United States.
  • Cancer patients should continue to see their treatment center care team and/or a local primary care provider after cancer treatment.

Reviewed: August 2023

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