Frm the 'American Cancer Society'
Many of the signs and symptoms of childhood leukemia are caused by a lack of normal blood cells, a result of the leukemia cells crowding out the normal blood cell-making cells in the bone marrow. As a result, a child may not have enough normal red blood cells, white blood cells, and blood platelets. These shortages show up on blood tests, but they can also cause symptoms. The leukemia cells may also invade other areas of the body, which can also cause symptoms.
Many of these symptoms have other causes as well, and most often they are not due to leukemia. Still, it's important to let your child's doctor know about them so that the cause can be found and treated, if needed.
Fatigue, pale skin: Anemia (a shortage of red blood cells) may cause a child to feel tired, weak, dizzy, or short of breath. It may also cause the skin to appear pale.
Infections and fever: A child with leukemia may develop fever. This is often caused by an infection, which may not improve even with antibiotics. This is because of a lack of normal white blood cells, which would normally help fight the infection. Although children with leukemia may have very high white blood cell counts, the leukemia cells do not protect against infection the way normal white blood cells do. Fever is also sometimes caused by the leukemia cells themselves releasing certain chemicals into the body.
Easy bleeding or bruising: A child with leukemia may bruise easily, have frequent nosebleeds and bleeding gums, or bleed excessively from small cuts. There may be pinhead-sized red spots on the skin caused by bleeding from tiny blood vessels. This comes from a lack of blood platelets, which normally stop bleeding by plugging holes in damaged blood vessels.
Bone or joint pain: Some children with leukemia will have bone pain or joint pain. This is from the buildup of leukemia cells near the surface of the bone or inside the joint.
Swelling of the abdomen: Leukemia cells may collect in the liver and spleen, causing them to enlarge. This may be noticed as a fullness or swelling of the belly. The lower ribs usually cover these organs, but when they are enlarged the doctor can often feel them.
Loss of appetite, weight loss: If the spleen and/or liver become large enough, they may press against other organs like the stomach. This can limit the amount of food that can be eaten, leading to a loss of appetite and weight loss over time.
Swollen lymph nodes: Some leukemias may spread to lymph nodes. The child, a parent, or a health care professional may notice swollen nodes as lumps under the skin in certain areas of the body (such as on the sides of the neck, in underarm areas, above the collarbone, or in the groin). Lymph nodes inside the chest or abdomen may also swell, but these can only be detected by imaging tests, such as CT or MRI scans.
Lymph nodes often enlarge when they are fighting an infection, especially in infants and children. Lymph nodes that grow as a reaction to infection are called reactive nodes or hyperplastic nodes. An enlarged lymph node in a child is more often a sign of infection than leukemia, but it should be checked by a doctor and followed closely.
Coughing or trouble breathing: The T-cell type of acute lymphocytic leukemia (ALL) often involves the thymus, which is a small organ in the chest behind the breastbone (sternum) and in front of the windpipe (trachea). Enlargement of the thymus or of lymph nodes inside the chest can press on the trachea. This can lead to coughing or trouble breathing.
Swelling of the face and arms: The superior vena cava (SVC), a large vein that carries blood from the head and arms back to the heart, passes next to the thymus. Growth of the thymus due to excess leukemia cells may press on the SVC, causing the blood to "back up" in the veins. This is known as SVC syndrome. It can cause swelling in the face, neck, arms, and upper chest (sometimes with a bluish-red skin color). It can also cause headaches, dizziness, and a change in consciousness if it affects the brain. The SVC syndrome can be life-threatening, and needs to be treated right away.
Headache, seizures, vomiting: Leukemia can spread outside the bone marrow. It may spread to the central nervous system (brain and spinal cord), the testicles, ovaries, kidneys, lungs, heart, intestines, or other organs. A small portion of children have leukemia that has already spread to the central nervous system when they are first diagnosed. Headache, trouble concentrating, weakness, seizures, vomiting, problems with balance, and blurred vision can be symptoms of central nervous system leukemia.
Rashes, gum problems: In children with acute myelogenous leukemia (AML), leukemia cells may spread to the gums, causing swelling, pain, and bleeding. Spread to the skin can cause small, darkly colored spots that can resemble common rashes. A collection of AML cells under the skin or in other parts of the body is called a chloroma or granulocytic sarcoma.
Extreme fatigue, weakness: One rare but very serious consequence of AML is extreme tiredness, weakness, and slurring of speech. This can occur when very high numbers of leukemia cells make the blood too "thick" and slow the circulation through small blood vessels of the brain.
If your child has signs and symptoms that suggest they may have leukemia, the doctor will want to get a thorough medical history, including how long the symptoms have been present and whether or not there is any history of exposure to risk factors. A family history of cancer, especially leukemia, may also be important.
During the physical exam, the doctor will focus on any enlarged lymph nodes, areas of bleeding or bruising, or possible signs of infection. The eyes, mouth, and skin will likely be looked at carefully, and a nervous system exam may be done. The abdomen will be felt for signs of an enlarged spleen or liver.
The doctor may also get blood samples to test your child's blood cell counts. If these are abnormal, the doctor may refer you to a pediatric oncologist, a doctor who specializes in treating cancers (like leukemia) in children.