General pathology · Paediatric pathology
Tumours of infancy and childhood !
- Topic
Children's cancers differ from adult ones: they arise from embryonic tissues, are often small round blue cell tumours, and many are cured.
Updated 2026-11-01
What it is
In childhood the leading cancers are leukaemias, central nervous system tumours, lymphomas and embryonal tumours (neuroblastoma, Wilms tumour, retinoblastoma, hepatoblastoma, rhabdomyosarcoma). The commonest benign tumours are haemangiomas. In high-income countries more than 80% of children with cancer are cured; in most low- and middle-income countries, fewer than 30%, according to WHO.
Key facts
- Infantile haemangioma: the commonest tumour of infancy; it grows in the first months and then involutes; it is GLUT1 positive.
- Neuroblastoma can mature into ganglioneuroma or regress spontaneously, especially in infants.
- Opsoclonus-myoclonus is a paraneoplastic syndrome typical of neuroblastoma.
- Many paediatric tumours relate to developmental genes and hereditary syndromes rather than to environmental carcinogens.
Malignant solid tumours of childhood
| Tumour | Typical age and site | Microscopy | Genetics and markers |
|---|---|---|---|
| Neuroblastoma | Under five; adrenal medulla and sympathetic chain | Small round blue cells; Homer Wright rosettes | MYCN amplification; urinary vanillylmandelic and homovanillic acid |
| Wilms tumour | Two to five years; kidney, palpable abdominal mass | Triphasic: blastema, stroma and epithelium | WT1 (11p13); WT2 (11p15) |
| Retinoblastoma | Early years; retina, leukocoria | Small blue cells; Flexner-Wintersteiner rosettes | RB1 (13q14) |
| Medulloblastoma | Children; cerebellum (posterior fossa) | Small blue cells; Homer Wright rosettes | Molecular subgroups (WNT, SHH, others) |
| Ewing sarcoma | Adolescents; shaft of long bones and pelvis | Small round blue cells | t(11;22) EWSR1-FLI1; CD99 |
| Osteosarcoma | Adolescents; metaphysis around the knee | Malignant cells that form osteoid | RB1 and TP53 |
| Rhabdomyosarcoma | Children; head and neck, genitourinary tract | Rhabdomyoblasts | Desmin, myogenin |
Markers
- CD99
- Desmin
- Myogenin
- GLUT1
- Synaptophysin
- Urinary catecholamines
- MYCN
- WT1
Clinical notes
- Neuroblastoma: the abdominal mass often crosses the midline; Wilms: a flank mass that does not.
- The survival gap between countries comes from late diagnosis, lack of access to treatment and treatment abandonment.
Test yourself
Think of the answer, then tap the question to see it.
What is the commonest extracranial solid tumour of childhood?
Neuroblastoma, which usually arises in the adrenal medulla.
Which three components are seen under the microscope in Wilms tumour?
Blastema, stroma and epithelium (a triphasic tumour).
Which second cancer threatens survivors of hereditary retinoblastoma?
Osteosarcoma, because they carry a mutated RB1 copy in every cell.
Which genetic change defines Ewing sarcoma?
The t(11;22) translocation, which fuses EWSR1 with FLI1.
Related
- Tumour suppressor genes: RB, TP53, APC, BRCA and the two-hit hypothesis
- Oncogenes: RAS, MYC, HER2, BCR-ABL and the table to know
- Naming tumours: -oma, carcinoma, sarcoma, and the misleading names
- Genomic imprinting: Prader–Willi and Angelman
- Hereditary cancer syndromes: the table to know
Related conditions
- Neuroblastoma
- Wilms tumour (nephroblastoma)
- Retinoblastoma
- Infantile hemangioma
- Acute leukaemia (AML and ALL)
- Childhood brain tumours (medulloblastoma, pilocytic astrocytoma, craniopharyngioma)
- Ewing sarcoma
- Osteosarcoma
- Hodgkin lymphoma
- Beckwith–Wiedemann syndrome
- Langerhans cell histiocytosis
Elsewhere in DurgiPedia
- Oncogenes and tumour suppressor genes
- Neural crest cells and their derivatives
- Kidney: pronephros, mesonephros, metanephros and ascent
- Eye: optic vesicle, optic cup and lens
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Cancer in Children and Adolescents (National Cancer Institute, 2026); Childhood cancer (World Health Organization, 2026); Neuroblastoma Treatment - NCI (National Cancer Institute, 2026); Wilms Tumor - NCI (National Cancer Institute, 2026).
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Representative model, for educational purposes only.