Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Leukaemia presentation and urgent investigation
Paediatrics and child health · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
!
Leukaemia with physiological compromise
Airway or breathing difficulty, orthopnoea, neurological change, retinal symptoms, shock, severe bleeding, sepsis, extreme leucocytosis or biochemical tumour lysis requires immediate specialist stabilisation.
Action: Use ABCDE, involve senior paediatrics, oncology, intensive care and haematology, obtain FBC and film plus renal, electrolyte, urate, phosphate, calcium, LDH, coagulation and group-and-save samples, and avoid steroids, sedation or excess fluid outside the agreed emergency plan.
Overview
Recognise childhood leukaemia when common symptoms form an abnormal pattern, order and act on urgent first-line tests without false reassurance, stabilise oncological emergencies safely, and preserve definitive diagnosis by coordinating early paediatric oncology care.
Look for trajectory and combination rather than one pathognomonic symptom. Ask when the child last seemed entirely well, whether fever or tiredness resolves, bruises are spontaneous, infections persist, pain wakes them or changes gait, and clothes or nappies feel tighter from abdominal enlargement. Record weight, appetite, night sweats, school attendance and paracetamol or steroid exposure. Parental repeated concern or several unexplained consultations lowers the threshold for escalation.
Examine the whole child: colour, petechiae, bruising, mucosal bleeding, lymph-node regions, liver, spleen, testes where clinically indicated, bones, joints, gait and neurological function. Assess cardiorespiratory status and ability to lie flat before requesting imaging or sedation. Leukostasis, sepsis, haemorrhage, tumour lysis and mediastinal obstruction are immediate priorities over naming the leukaemia subtype.
Practice
Two practice questions
Your practice draft is saved in this browser.
Question 1 of 2
0 correct
Paediatrics and child healthOriginal SBA
Immediate leukaemia referral
A 6-year-old has unexplained petechiae and newly palpable hepatosplenomegaly. The child is currently haemodynamically stable. What is the correct next action under NICE NG12?
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.
NICE separates time-critical routes. Unexplained petechiae or hepatosplenomegaly requires immediate specialist assessment. Pallor, persistent fatigue, unexplained fever, persistent infection, generalised lymphadenopathy, persistent unexplained bone pain, bruising or bleeding requires an FBC within 48 hours. An abnormal result is discussed with paediatrics or haematology the same day; a reassuring result does not end safety-netting if the clinical pattern progresses.
Obtain FBC, film and reticulocytes before transfusion where this does not delay resuscitation, and inform the laboratory that acute leukaemia is suspected. Pancytopenia is common but the white count may be low, normal or high. Blasts support the diagnosis but may be absent from peripheral blood. Add renal and liver profile, CRP, LDH, urate, phosphate, calcium, coagulation and group and save; cultures and lactate follow fever or physiological concern.
Bone-marrow aspirate and trephine under the paediatric oncology pathway provide reference-standard morphology and material for flow cytometry, cytogenetics, molecular classification and measurable residual disease markers. A lumbar puncture assesses CNS disease and delivers protocol treatment but only after stability, platelet safety and procedural planning. Chest radiograph is obtained early when T-lineage disease or mediastinal symptoms are possible, but the child must remain in their position of comfort.
Before definitive therapy, stabilise carefully. Suspected sepsis receives immediate antibiotics. Correct symptomatic bleeding with oncology and transfusion advice. High tumour burden triggers strict fluid balance, repeated tumour-lysis biochemistry and timely urate-lowering therapy. Avoid unnecessary potassium or phosphate in IV fluids. In hyperleucocytosis, avoid unplanned red-cell transfusion or aggressive fluid loading because viscosity and pulmonary compromise can worsen; involve critical care early.
Treatment is subtype- and risk-specific multi-agent chemotherapy delivered through a principal treatment centre, with supportive transfusion, infection prophylaxis, nutrition, fertility and psychosocial care. Genetic features and early measurable residual disease refine intensity; therefore pre-treatment diagnostic integrity matters. Support the child's assent or consent according to maturity, provide age-appropriate explanations, and coordinate school, siblings, community nursing and GP communication from diagnosis through survivorship.
Key points
Childhood leukaemia often presents as a cluster: pallor and fatigue, bruising or petechiae, fever or infection, bone pain, lymphadenopathy and hepatosplenomegaly.
Immediate specialist assessment is required for unexplained petechiae or hepatosplenomegaly; other key unexplained features warrant a very urgent FBC within 48 hours under NICE NG12.
First-line tests are FBC with manual film, reticulocytes and urgent senior interpretation; one normal count or absence of circulating blasts does not exclude early leukaemia.
Check renal and liver function, LDH, urate, potassium, phosphate, calcium, coagulation and group and save at urgent assessment to identify organ risk and tumour lysis.
Reference-standard diagnosis is specialist bone-marrow morphology with flow cytometric immunophenotyping, cytogenetics and molecular testing.
Do not start corticosteroids before diagnostic sampling unless the paediatric oncology team directs it; steroids can clear blasts, alter risk classification and complicate tissue diagnosis.
Do not perform a lumbar puncture in unstable physiology, severe thrombocytopenia, raised intracranial pressure or before the oncology protocol and haemostatic plan is agreed.
A mediastinal mass creates a positional and anaesthetic emergency: keep the child in the position of comfort and avoid sedation or lying flat until specialist airway planning.
Aetiology
01
Somatic precursor-cell mutation
Acquired genetic and epigenetic changes give a lymphoid or myeloid precursor self-renewal, survival and proliferative advantage within marrow.
02
Acute lymphoblastic leukaemia
ALL arises from B- or T-lymphoid precursors and accounts for most childhood leukaemia, usually developing over days to weeks.
03
Acute myeloid leukaemia
AML arises from myeloid precursors and is less common but often presents with rapid marrow failure and tissue infiltration.
04
Predisposing conditions
Down syndrome, inherited marrow-failure or cancer-predisposition syndromes, prior cytotoxic treatment and rare familial variants increase risk, although most children have no identifiable cause.
Pathophysiology
1
Marrow replacement
Expanding blasts crowd and suppress normal erythroid, myeloid and megakaryocyte production, causing anaemia, infection susceptibility and thrombocytopenic bleeding.
2
Tissue infiltration
Leukaemic cells enlarge liver, spleen, lymph nodes, testes and mediastinal thymic tissue and can enter the central nervous system.
3
Bone and periosteal pressure
Marrow expansion and infiltration produce limb, back or joint pain, night waking, limp and refusal to walk.
4
High-cell-burden physiology
Rapid turnover releases potassium, phosphate and nucleic acids, while extreme circulating blasts increase viscosity and impair cerebral or pulmonary microcirculation.
Clinical features and red flags
Marrow-failure cluster
Pallor and fatigue, fever or infection, and bruising or petechiae reflect loss of three normal blood-cell functions.
Infiltrative pattern
Generalised nodes, hepatosplenomegaly, testicular change or a mediastinal mass reflects extramedullary blast accumulation.
Musculoskeletal presentation
Night pain, limp, refusal to walk or multifocal bone and joint symptoms can precede striking blood-count abnormalities.
Hyperleucocytosis
Respiratory distress, visual symptoms, headache or neurological change with extreme leucocytosis suggests leukostasis rather than benign count elevation.
Mediastinal danger
Orthopnoea, stridor, cough, facial swelling and venous distension indicate airway or great-vessel compression and positional risk.
Red flags requiring action
Unexplained petechiae or hepatosplenomegaly in a child or young person meets NICE criteria for immediate specialist assessment for leukaemia.
Pallor, persistent fatigue, unexplained fever, persistent infection, generalised lymphadenopathy, bone pain, bruising or bleeding requires a very urgent FBC within 48 hours.
Breathlessness, orthopnoea, facial or neck swelling, venous distension or stridor
Investigations
01First-line urgent FBC with manual filmFirst stepFirst line
Why
Detect cytopenias, leucocytosis and abnormal precursors and trigger same-day specialist action.
Interpretation and limitations
White count may be high, normal or low and peripheral blasts may be absent; interpret every lineage with the clinical pattern.
02Reticulocyte count
Why
Assess whether anaemia reflects suppressed marrow production or a peripheral destructive response.
Interpretation and limitations
An inappropriately low count supports marrow failure, although bleeding, haemolysis and transfusion can alter the result.
03Tumour-lysis and organ baseline
Why
Identify electrolyte, urate, renal, hepatic and cell-turnover risk before diagnostic procedures or therapy.
Interpretation and limitations
Rising potassium, phosphate, urate, LDH or creatinine and falling calcium requires immediate tumour-lysis management.
04Coagulation, group and save and cultures
Why
Prepare for bleeding support and detect infection or DIC in an unstable or febrile child.
Interpretation and limitations
Do not delay antibiotics for cultures, and involve transfusion laboratory early when antibodies or urgent support is possible.
Differential diagnosis
01
Viral infection
Fever, transient cytopenias and lymphadenopathy are common, but progressive multisystem signs, organomegaly or failure to recover require repeat examination and blood count.
02
Immune thrombocytopenia
A well child with isolated thrombocytopenia and a normal film fits ITP; bone pain, organomegaly or other affected lineages do not.
03
Aplastic anaemia
Pancytopenia without blasts or substantial organomegaly suggests marrow aplasia, confirmed by specialist marrow morphology and cellularity.
04
Juvenile idiopathic arthritis or osteomyelitis
Focal inflammatory findings can mimic bone pain, but nocturnal, multifocal or disproportionate pain with blood-count change warrants malignancy exclusion.
05
Haemolysis or nutritional anaemia
Jaundice, reticulocytosis, microcytosis or low ferritin support alternatives, but these do not explain blasts, thrombocytopenia and organomegaly together.
Management
01Immediate cancer featuresRefer nowFirst stepUnexplained petechiae or hepatosplenomegaly is found.+
1Contact paediatrics for immediate specialist assessment rather than waiting for a routine clinic.
2Obtain urgent FBC and film if this does not delay transfer and communicate the clinical concern to the laboratory.
3Assess and stabilise bleeding, infection, tumour lysis, breathing and neurological complications concurrently.
02Very urgent symptom clusterCount blood cells within 48 hoursPallor, fatigue, fever, persistent infection, generalised nodes, bone pain, bruising or bleeding is unexplained.+
1Arrange FBC and film within 48 hours and provide explicit access if the child deteriorates sooner.
2Discuss abnormal counts or film with paediatrics or haematology the same day.
3
Complications
01
Sepsis and haemorrhage
Neutropenia, immune dysfunction, mucosal injury and thrombocytopenia make infection and bleeding leading immediate threats before and during treatment.
02
Tumour lysis syndrome
Spontaneous or treatment-triggered cell breakdown causes electrolyte disturbance, urate nephropathy, arrhythmia, seizure and acute kidney injury.
03
Leukostasis
Extreme blast burden obstructs pulmonary and cerebral microcirculation, producing hypoxia, respiratory failure, visual change or neurological deficit.
04
Mediastinal compression
T-cell disease can narrow airway, great vessels and cardiac inflow; lying flat, sedation or general anaesthesia may precipitate collapse.
05
Treatment and late effects
Infection, organ toxicity, thrombosis, infertility, neurocognitive change, second malignancy and psychosocial disruption require risk-based survivorship care.
Monitoring and follow-up
Repeat observations, neurological examination, respiratory status, bleeding assessment and fluid balance during urgent stabilisation.
Trend FBC, potassium, phosphate, calcium, urate, creatinine and LDH at a frequency matched to tumour burden and treatment phase.
Monitor transfusion response and reactions with the oncology and transfusion plan, avoiding unnecessary volume.
During therapy, follow protocol-defined counts, organ toxicity, infection prophylaxis and measurable residual disease milestones.
Track weight, height, nutrition, pubertal development, fertility discussion, activity and school attendance.
Provide central-line education, temperature thresholds and direct-access contact details before community care.
After treatment, use risk-based survivorship surveillance for cardiac, endocrine, neurocognitive, bone and second-cancer effects.
Special situations
The white count can be normal
Leukaemia is marrow disease; absence of leucocytosis or peripheral blasts cannot safely exclude it.
Bone pain can lead
A child may limp or stop walking before pallor, bruising or a dramatic FBC makes the pattern obvious.
Steroids can erase evidence
Lymphoblasts are steroid-sensitive, so unsupervised treatment may obscure diagnosis and alter risk assessment.
Position is physiology
A child with mediastinal compression may decompensate when supine or sedated despite appearing comfortable upright.
Urgency is compatible with reassurance
Explain honestly that most urgent referrals are not cancer while making the investigation timeframe explicit.
Common pitfalls
01
Excluding leukaemia because the white count or first film is normal.
02
Attributing persistent bone pain and limp to growing pains without reassessment.
03
Starting corticosteroid for presumed ITP, wheeze or lymphadenopathy before oncology discussion.
04
Sedating or laying flat a child with orthopnoea and a mediastinal mass.
05
Giving routine red cells for hyperleucocytosis without specialist viscosity assessment.
06
Performing lumbar puncture before physiological and haemostatic safety is established.
07
Sending a standard two-week adult-style referral instead of using paediatric immediate or 48-hour routes.
08
Failing to safety-net a persistent concerning pattern after a reassuring initial FBC.
Hyperleucocytosis is managed in a principal treatment centre with controlled fluids, tumour-lysis prevention and protocol-specific cytoreduction; routine red-cell transfusion can worsen viscosity and needs specialist approval.
Explain that urgent referral investigates serious possibilities and that many referred children will not have cancer; give families a named contact and clear next steps.
may indicate an anterior mediastinal mass and unsafe airway compression.
Severe headache, confusion, visual change, focal deficit or respiratory distress with marked leucocytosis suggests leukostasis and needs critical-care oncology input.
Hyperkalaemia, hyperphosphataemia, hypocalcaemia, hyperuricaemia, rising creatinine or oliguria signals spontaneous or treatment-related tumour lysis.
Fever or haemodynamic change with neutropenia or dysfunctional malignant white cells should be treated as possible sepsis, even when inflammatory signs are muted.
05
Reference-standard bone marrow assessment
Why
Confirm acute leukaemia and determine lineage, genetics, risk markers and measurable residual disease targets.
Interpretation and limitations
Morphology integrates with flow cytometry, cytogenetic and molecular data; no isolated peripheral result substitutes for this classification.
06Chest radiograph for mediastinal risk
Why
Identify mediastinal widening before anaesthesia or procedures when T-lineage disease is possible.
Interpretation and limitations
A mass plus orthopnoea or airway signs mandates specialist anaesthetic planning and avoidance of routine sedation.
Repeat examination and reconsider testing when symptoms persist despite an initially reassuring result.
03Mediastinal massProtect the airway before tissue diagnosisOrthopnoea, stridor, facial swelling or chest imaging suggests a mediastinal mass.+
1PreferredKeep the child upright or in their preferred position and avoid forced supine positioning.
2Call oncology, anaesthesia and intensive care before sedation, general anaesthesia or invasive sampling.
3Choose the safest diagnostic tissue or marrow approach through the specialist MDT.
04High burden emergencyPrevent leukostasis and lysis injuryExtreme leucocytosis, neurological or pulmonary features, or biochemical lysis risk is present.+
1Transfer urgently to the principal treatment centre with critical-care involvement.
2Use controlled hydration, frequent biochemical monitoring and protocol-directed urate therapy.
3Avoid routine red-cell transfusion, steroids or cytoreduction unless directed by paediatric oncology.