Signs and symptoms of acute lymphoblastic leukemia (ALL) in children

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Learn about the signs and symptoms of acute lymphoblastic leukemia (ALL), which can cause physical and neurological changes in your child.

Key points

  • Fever is the most common symptom of ALL.
  • Children with ALL may initially have fluctuating symptoms.
  • Leukemia can have physical and sometimes neurological symptoms.
  • It is rare for there to be no early signs or symptoms of leukemia.

The signs and symptoms of ALL can vary. In most cases they develop rapidly; this is called acute onset. Sometimes symptoms can develop slowly, depending on how much the leukemia cells have spread inside the bone marrow and to other organs.

Fever is the most common symptom. It can be caused by an infection. Leukemia cells can also excrete substances called cytokines that can trigger the fever.

Other common symptoms include:

  • fatigue, lethargy, and loss of appetite
  • shortness of breath during physical activity
  • bone pain, which may cause your child to limp or unable to walk

At first, your child’s symptoms may fluctuate daily. They may feel exhausted one day and fine the following day.

Leukemia can also cause physical changes in your child, including:

  • pale complexion
  • bone tenderness, particularly in long bones such as the calves, upper arm, fingers, and toes
  • pinhead-sized red spots under the skin, called petechiae; these indicate bleeding under the skin
  • bruising or unusual bleeding from minor cuts or nose bleeds
  • enlarged liver or spleen, which causes the abdomen to swell
  • enlarged lymph nodes
  • painless swelling in the testicles, caused by leukemic cells accumulating inside the testes

In some cases, leukemic cells can invade the central nervous system (CNS). When leukemia cells are found in the spinal fluid, the child may or may not have neurological symptoms. Some of the neurological symptoms that are seen with CNS leukemia are:

  • headache
  • vomiting
  • weakness and difficulty maintaining balance
  • blurred vision, double vision, sensitivity to light, or eye pain; this may be caused by leukemia cells infiltrating the parts of the eye or nerves
  • seizures

Other less common symptoms of leukemia include:

  • red or blue-red bumpy lesions in the skin, called subcutaneous nodules; this happens when leukemia cells infiltrate the skin
  • enlarged salivary glands
  • painful erection of the penis (priapism)

Sometimes, leukemic cells can infiltrate the tonsils, adenoids, and appendix. This may lead to surgical intervention before leukemia is diagnosed.

Rarely, there are no early signs or symptoms of leukemia and the disease is detected during routine blood work.


Some children may develop masses in the abdomen, causing pain or discomfort. Fluid can also build up inside the abdomen, called ascites, which causes pressure on the abdomen and sometimes shortness of breath. Children with ascites can also have fluid in their lungs, which is called pleural effusion.


3% of children with B-cell ALL (leukemia that starts in B-cells) will have some leukemia cells in the spinal fluid and/or cranial nerve palsies. Cranial nerve palsy is a nerve disorder in which the brain nerves lose control of the muscles in the face. For example, children with cranial nerve palsy have difficulty controlling the way their eyes move or forming facial expressions, such as smiling.

T-cell ALL

In T-cell ALL (leukemia that starts in T-cells), leukemic cells can accumulate in the thymus, causing it to enlarge. The thymus is a small organ where T cells mature. It is found in the upper chest, just behind the sternum (breastbone); this area is called the mediastinum. The enlarged thymus forms a lump called a mediastinal mass.

  • If the mass puts pressure on the trachea (windpipe), it can cause coughing, shortness of breath, pain, or difficulty swallowing (dysphagia).
  • If the mass puts pressure on the superior vena cava, it can cause the head and arms to swell. This is called superior vena cava syndrome. The superior vena cava is a short, wide vein that carries blood from the upper body to the heart.

Leukostasis syndrome

In rare cases, leukemic cells can multiply into extremely large numbers (hyperleukocytosis). When large clumps of leukemic cells enter small blood vessels, they can cause problems in other parts of the body such as the lungs, nervous system, heart and/or eyes. This is called leukostasis syndrome (symptomatic hyperleukocytosis).

Leukostasis syndrome can cause various symptoms in different parts of the body. If your child develops any of these symptoms, take them to emergency right away.

  • shortness of breath: this happens when tissues inside the body are not getting enough oxygen, causing a condition called hypoxia
  • coughing
  • headache
  • vertigo
  • hearing loss
  • unbalanced walking (ataxia)
  • double vision
  • confusion
  • fainting
  • seizures
  • drowsiness
  • swelling of limbs
  • chest pain, which happens when the heart is not getting enough blood; this is called angina
  • abnormal heart beats
  • hemorrhage (bleeding) in the retina, which is the light-detecting layer at the back of the eye
  • retinal vein thrombosis (blockage of a vein in the retina)

Other symptoms of leukostasis syndrome include bleeding from the mouth, nose, gut, lungs, or brain. This syndrome may also affect the kidneys.

Tumour lysis syndrome

Hyperleukocytosis can also cause leukemic cells to release substances such as uric acid, potassium, and phosphate into the blood. This is known as tumour lysis syndrome. In children with hyperleukocytosis, this can be severe. If untreated, this can potentially lead to kidney failure.

Your child requires immediate medical attention if they develop any of the above symptoms.

Last updated: March 6th 2018