Yes, leukemia can be missed in a blood test, especially in early stages or if cancer cells remain in the bone marrow rather than circulating in the blood, leading to normal counts in a Complete Blood Count (CBC). While blood tests are crucial for screening, they aren't 100% accurate, and a doctor must interpret results alongside symptoms, medical history, and sometimes a bone marrow biopsy for definitive diagnosis, as leukemia can hide in the marrow.
But in some patients, the leukemia stays in the bone marrow and is not found in blood. In that case, flow cytometry may be performed on bone marrow (usually taken from the hip bone) or other tissue, such as a piece of a lymph node.
Common leukemia signs and symptoms include:
Leukemia in children is most often diagnosed based on blood or bone marrow results. In rare cases, a large lymph node may be the main symptom of a new leukemia. In these cases, a lymph node biopsy may be done to make a diagnosis.
Fever and frequent infections due to low counts of healthy white blood cells. Excessive sweating or night sweats. Easy bleeding and bruising, including bleeding of the gums due to low platelet levels. Recurrent nose bleeds.
It is certainly not unusual to sweat during the night, especially in the summer when your room or bedding becomes too hot. However, severe night sweats that occur to an extent that your bed sheets or pyjamas become soaking wet, despite sleeping in a cool environment, can sometimes be a sign of leukaemia.
Though it's most commonly found on the arms and legs, a petechiae leukemia rash may also appear on the buttocks, the inside of the mouth or the eyelids. Though it looks like a rash of pinhead-sized spots, petechiae is actually a cluster of tiny bruises.
Symptoms of childhood leukemia
Coughing or trouble breathing. Headaches, seizures, balance problems, visual changes, or vomiting (if the leukemia spreads to the brain and spinal cord) Loss of appetite or weight. Pain in the bones and joints.
Most people with leukemia are over 60. Although you can develop it at any time of life, most types are rarely diagnosed in people under 40.
Bone marrow test.
Your doctor may recommend a procedure to remove a sample of bone marrow from your hipbone. The bone marrow is removed using a long, thin needle. The sample is sent to a laboratory to look for leukemia cells.
In the initial stages of diagnosing acute myeloid leukaemia (AML), your GP will check for physical signs of the condition and arrange for you to have blood tests. A high number of abnormal white blood cells, or a very low blood count in the test sample, could indicate leukaemia.
Some people with leukemia or myelodysplastic syndromes have bone or joint pain. This bone pain is most often felt in the long bones of the arms and legs, in the ribs, and in the breastbone.
The most common leukemia biomarkers are CD (cluster of differentiation) markers, an extremely diverse series of membrane proteins predominantly expressed on the leukocyte surface. CD markers are mostly useful for classifying white blood cells (WBC) and especially important for diagnosis of lymphomas and leukemias.
Chronic lymphocytic leukemia (CLL) is often a silent disease during the initial stages, with many patients having no noticeable symptoms. CLL is commonly detected by accident when routine blood testing reveals an elevated lymphocyte count (lymphocytosis).
Leukemia symptoms
Not all children with leukemia have abnormal blood counts, but they may have other signs of leukemia found through a physical exam or by looking at their blood cells under a microscope. If your child's doctor suspects leukemia, we will remove a sample of bone marrow for analysis.
Leukemia starts in the soft, inner part of the bones (bone marrow), but often moves quickly into the blood. It can then spread to other parts of the body, such as the lymph nodes, spleen, liver, central nervous system, and other organs.
Acute leukemias
Who is most at risk?
Leukemia symptoms often develop suddenly within a few days or weeks. Early indicators can be difficult to recognize because they often mimic the symptoms of influenza and other more common, less serious conditions.
Leukemia is commonly misdiagnosed as the following conditions:
Common symptoms of leukemia in children include feeling tired and weak, easy bruising or bleeding, and frequent or long-lasting infections. Leukemia is diagnosed with blood and bone marrow tests. Imaging may be done to look for signs of leukemia in different parts of the body.
Itching itself can range from mild to severe and can occur anywhere on your body. Some common areas where people with blood cancer experience itching are on the torso, back, legs and arms. The sensation can come and go in short bursts or it may last for long periods of time.
Leukemia spots, called petechiae, look like tiny, flat, pinpoint-sized red, purple, or brown dots that appear in clusters, often on arms, legs, or the mouth, and importantly, do not fade or turn white when pressed. They form from broken capillaries due to low platelets, resembling a rash but are actually tiny bleeds under the skin.
They occur in unusual places – In cases of leukaemia, quite often bruises will appear in places that you wouldn't normally expect, especially; the back, legs, and hands.