title: "Week 6: Haematology, Neurology & Oncology"

Week 6: Haematology, Neurology & Oncology

1. Haematology

Coagulation Studies Review

Test	Pathway	Factors	Normal	Monitors
APTT (Activated Partial Thromboplastin Time)	Intrinsic + Common	12, 11, 9, 8 + X, V, II, I	~45 seconds	Heparin, Haemophilia
PT/INR (International Normalised Ratio)	Extrinsic + Common	TF, 7 + X, V, II, I	~15 seconds	Warfarin

Clinical Pearl

Mixing study: If abnormal coagulation corrects with mixing, it's a factor deficiency. If it doesn't correct, there's an inhibitor (antibodies).

Anaemia

There is a physiological Hb nadir at 6-8 weeks old due to decreased EPO (higher O2), transitioning from HbF to HbA, and haemodilution.

Causes by Age:

Age	Production	Haemolysis	Blood Loss
Newborn	Congenital anaemias, TORCH	Rh/ABO incompatibility	Fetomaternal haemorrhage
Infant/Toddler	Iron/B12 deficiency, TEC	Hereditary spherocytosis, G6PD	Dietary, cow's milk
Older child	Iron deficiency, BM disorders	Autoimmune haemolytic	Menorrhagia, IBD

Four Critical Parameters in Anaemia

MCV (micro/macro/normocytic)
Reticulocyte count (regenerative vs non-regenerative)
Other cell lines (isolated vs pancytopaenia)
Blood film review

Classic Presentations:

Condition	Presentation
Iron deficiency	Pallor, pica, glossitis in toddler with dietary insufficiency or chronic blood loss
Sickle cell disease	Painful vaso-occlusive crises, dactylitis, chronic anaemia, infections
Thalassaemia major	Severe pallor, failure to thrive, hepatosplenomegaly, frontal bossing
Hereditary spherocytosis	Haemolytic anaemia, jaundice, splenomegaly, FHx
G6PD deficiency	Acute haemolysis triggered by infections, drugs, or fava beans
Diamond-Blackfan	Macrocytic anaemia, congenital anomalies, reticulocytopenia

Clinical Pearl

Transient erythroblastopaenia of childhood: Otherwise well child with recent viral infection who is a bit pale. Isolated anaemia, low reticulocytes. Recovers spontaneously.

Iron Deficiency Anaemia

Most common cause of anaemia in children. In infants/children: nutritional (excess cow's milk, insufficient iron-rich foods). In adolescents: malabsorption and blood loss.

Blood film: Hypochromic, microcytic with teardrop and pencil cells

Management: Dietary advice, oral iron supplementation. IV iron only if oral contraindicated or severe ongoing loss.

Bleeding Disorders

Primary haemostasis = platelets + vWF (platelet plug). Secondary haemostasis = coagulation factors (fibrin thrombus).

Type	Mechanism	Examples
Platelet	Number or function	Thrombocytopaenia (ITP, TTP), platelet dysfunction
Coagulation	Factor deficiency	Haemophilia A (VIII), B (IX), von Willebrand disease
Vascular	Fragile vessels	HSP, Vitamin C deficiency, connective tissue disorders

Immune Thrombocytopaenic Purpura (ITP)

ITP: Most common thrombocytopaenia in healthy children. Usually 1-4 weeks post-viral infection. Self-limiting - 80% resolve within 6 months.

Source: Local paediatric haematology guideline/teaching.

Features: Petechiae, bruising, mucosal bleeding. Platelets low, but everything else is normal.

Warning

Red flags for NOT ITP: Lymphadenopathy, hepatosplenomegaly, abnormal film, abnormal other cell lines - suspect malignancy.

Haemophilia

Haemophilia A (Factor VIII) is more common than Haemophilia B (Factor IX). Both are X-linked recessive. Present with prolonged APTT (Activated Partial Thromboplastin Time).

Presentation: Deep bleeding (joints, muscles), prolonged bleeding post-surgery, easy bruising

2. Neurology

Seizures - Emergency Management

Seizures occur in 1 in 20 (5%) children. Most are febrile seizures - brief and self-limiting, ceasing within 5 minutes.

Source: Local paediatric neurology teaching.

Seizure Rule of 5's

5% of population have seizures
Medicate if seizure lasts ≥5 minutes
1st line: 2 doses benzodiazepine, 5 minutes apart

Emergency Management (ABCD):

A: Clear airway, lie on side
B: Give oxygen
C: IV access, 20mL/kg saline if shock
D: Check BSL (Blood Sugar Level) - if <3.5, give 10% dextrose 5mL/kg

Status Epilepticus

Convulsive status epilepticus: Ongoing convulsive seizure ≥5 minutes, or recurrent seizures without return to baseline. Bimodal peaks: toddlers and elderly.

Management:

1st line: 2 doses IV midazolam, 5 minutes apart (or buccal midazolam if no IV)
2nd line: Phenytoin or levetiracetam (phenobarbitone in neonates)
3rd line: RSI (Rapid Sequence Intubation) + intubation with thiopentone

Febrile Convulsions

Simple febrile convulsion: 6 months - 6 years, generalised tonic-clonic, <15 minutes, fever >38.5°C, no CNS infection, doesn't recur in same illness.

Source: Local paediatric febrile seizure guideline (e.g., RCH CPG).

Clinical Pearl

Antipyretics do NOT help prevent febrile convulsions - the pathophysiology is linked to rapid rise in temperature, not the absolute temperature.

Complex febrile convulsion features:

Focal features
Duration >15 minutes
Recurrence within same febrile illness
Children with all 3 features have 50% chance of epilepsy

Warning

Red flags:

Seizure after vaccination or prolonged hemiclonic = consider Dravet syndrome
Incomplete recovery = CNS (Central Nervous System) infection, stroke, or bleed

Paroxysmal Disorders

Many conditions mimic seizures but are NOT epileptic. History and home video are key to diagnosis.

Differentials by age:

Neonates	Infants	Children	Adolescents
Jitteriness	Breath-holding spells	Staring/daydreaming	Syncope
Benign sleep myoclonus	GI reflux	Tics	Non-epileptic seizures
Startle reflex	Shuddering attacks	Migraines	Parasomnias

Breath-Holding Spells

6 months - 2 years. Trigger (fear, frustration) → crying → expiratory breath hold → stiff, loss of awareness → clonic jerks. Benign, no long-term effects.

Iron deficiency may be involved - correction is helpful
Always check ECG (Electrocardiogram) to rule out arrhythmia

Tics

Clinical Pearl

Tourette Syndrome: Motor + vocal tics in bouts, nearly daily for >1 year, beginning before 18 years. 90% have neurodevelopmental comorbidities (ADHD (Attention-Deficit/Hyperactivity Disorder), OCD, autism).

Source: DSM-5-TR; local paediatric neurology/psychiatry teaching.

Epilepsy Syndromes

Infantile Spasms (West Syndrome)

Warning

Neurological emergency! Prompt treatment required to prevent irreversible developmental effects.

West syndrome triad:

Epileptic spasms (1-2 seconds, repetitive)
Hypsarrhythmia on EEG
Developmental regression

Affects 1 in 3500 infants, onset 1st year of life
80% symptomatic (HIE, tuberous sclerosis, metabolic)
Treatment: Steroids (prednisolone or ACTH) or vigabatrin (for tuberous sclerosis)

Childhood Absence Epilepsy

3-8 years old. Sudden cessation of consciousness with subtle automatisms, brief (5-15 seconds), multiple times per day. Hyperventilation is a trigger. EEG shows 3Hz spike-and-wave.

Cerebral Palsy

Non-progressive motor disorder from injury to the developing brain. Prevalence 2 per 1000 live births. Classified by topography (hemi/di/quadriplegia) and motor type (spastic most common).

Risk factors: Prematurity, low birthweight, perinatal asphyxia, neonatal encephalopathy

3. Oncology

1 in 600 children will develop cancer. Cancer is the second leading cause of death in children (after accidents). Unlike adults, paediatric cancer is rarely carcinoma and not associated with lifestyle factors.

Clinical Pearl

Many paediatric cancers are highly chemo-sensitive with 75% cured permanently.

Cardinal Symptoms of Childhood Cancer

Persistent/recurrent fever without cause
Persistent pain (bone, night, headache)
Mass or organomegaly
Purpura or unexplained bleeding
Pallor/anaemia
Strabismus
Neuromotor changes
Weight loss

Types of Paediatric Cancer

Type	%	Key Features
Leukaemia	30%	80% ALL, 20% AML
Brain tumours	~20%	More posterior fossa in children
Neuroblastoma	~8%	Neural crest origin, pre-school age
Lymphoma	~10%	Hodgkin's in teens, NHL various
Sarcomas	~7%	Bone (Ewing's, osteosarcoma) or soft tissue (rhabdomyosarcoma)
Wilms' tumour	~5%	Kidney, 1-7 years old

Acute Lymphoblastic Leukaemia (ALL)

Commonest childhood malignancy. Presents with anaemia, thrombocytopaenia, bruising, fever, bone pain, lymphadenopathy, hepatosplenomegaly.

Symptoms arise from bone marrow infiltration
Diagnosis: Bone marrow biopsy, LP for CNS (Central Nervous System) disease
Poor prognostic factors: <2 or >10 years, high WCC (White Cell Count), Philadelphia chromosome, CNS (Central Nervous System) disease
Treatment: 2 years total (induction, intensification, maintenance)
75% cured

Clinical Pearl

DDx for ALL: ITP, neutropaenias, infectious mononucleosis, systemic JIA

Neuroblastoma

Tumour of neural crest cells (adrenal medulla, sympathetic ganglia). Pre-school children. Most are abdominal, malignant.

>12 months: worst prognosis - flank mass, bony metastases ("black eyes", pain, limp)
<12 months: better prognosis
Bedside test: Urine catecholamines (HVA and VMA)

Wilms' Tumour

Kidney tumour in 1-7 year olds. Large, painless flank mass, haematuria. Generally good prognosis.

Oncological Emergencies

Febrile Neutropaenia

Warning

Fever is a medical emergency in neutropaenic patients. May be the only sign of severe infection - signs of inflammation are attenuated.

WCC (White Cell Count) is lowest 7-10 days after chemotherapy. Mortality typically from gram-negative infections (Pseudomonas, E. coli, Klebsiella).

Management:

ABCs, blood cultures (including from CVAD)
Antibiotics within 60 minutes: Anti-pseudomonal beta-lactam (pip-taz) + gentamicin
Add vancomycin if shock or infected line
Do not wait for lab results

Clinical Pearl

Children may acutely deteriorate after antibiotics due to septic shower/endotoxin release - monitor closely!

Spinal Cord Compression

Warning

Medical emergency! Occurs in 3-5% oncology patients. Needs urgent treatment to avoid irreversible damage.

Source: Local paediatric oncology guideline.

Red flags: Back pain, abnormal gait, limb weakness, sensory deficit, developmental regression

Mediastinal Mass / SVCO

Warning

Anterior mediastinal mass is an oncologic emergency. Increased risk of cardiorespiratory arrest, especially under GA/sedation. Do NOT force the child to lie flat.

>80% of mediastinal masses are malignant (typically haematological)
CT (Computed Tomography) may be done prone, lateral, or semi-upright

Raised Intracranial Pressure

Red flags:

Persistent vomiting, worse in morning
Worse with coughing
Personality change
Hypertension, papilloedema
Gait changes, visual disturbance
Drowsiness/reduced LOC (Loss of Consciousness)

Management: MRI (Magnetic Resonance Imaging), elevate head, dexamethasone, IV (Intravenous) fluids 75% maintenance, hypertonic saline, urgent neurosurgery

Brain Tumours

Second most common paediatric malignancy (after leukaemia). Unlike adults, paediatric brain tumours are predominantly posterior fossa (infratentorial), causing obstructive hydrocephalus.

Tumour	Location	Age	Features
Pilocytic astrocytoma	Posterior fossa (cerebellum)	5-15 years	Cystic, enhancing nodule. Excellent prognosis.
Medulloblastoma	Posterior fossa (4th ventricle)	3-8 years	Aggressive, CSF seeding. Needs surgery + chemo + radiation.
Ependymoma	4th ventricle	Under 5 years	Arises from ependymal lining, extends through foramina
Craniopharyngioma	Suprasellar	5-14 years	Calcified, visual field defects, growth failure, diabetes insipidus
Brainstem glioma	Pons	5-10 years	Cranial nerve palsies, ataxia, long tract signs. Poor prognosis.

Warning

Presentation red flags for brain tumour:

Morning headache worse on coughing/straining (raised ICP (Intracranial Pressure))
New-onset seizures with focal features
Personality/behavioural change
Persistent unexplained vomiting (especially morning)
Progressive ataxia or cranial nerve palsies
Growth failure or precocious puberty (suprasellar tumours)

Clinical Pearl

In infants, raised ICP (Intracranial Pressure) may present with increasing head circumference, bulging fontanelle, and sunsetting eyes (failure of upward gaze) rather than classic headache.

Tumour Lysis Syndrome

Tumour lysis syndrome: Rapid cell death (often after starting chemotherapy) releases intracellular contents. Classic metabolic derangement: high K+, high phosphate, high urate, low calcium. Can cause acute kidney injury and cardiac arrhythmia.

Prevention: Aggressive hydration, allopurinol or rasburicase (for high-risk patients)