Wilms Tumour vs Neuroblastoma
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Direct answer
Wilms tumour (nephroblastoma) and neuroblastoma are the two classic abdominal malignancies of childhood, and the exam discriminates them on a handful of features. Wilms tumour is a renal tumour of children around three to five years presenting as a smooth, firm, non-tender flank mass, with haematuria and hypertension as associates; neuroblastoma arises from the adrenal medulla or sympathetic chain in younger children, often crosses the midline, calcifies and secretes catecholamine metabolites measured as urinary vanillylmandelic acid. Both are imaged by CT or MRI, but their treatment and prognosis differ substantially.
What you must remember
- Age and origin: Wilms tumour peaks around three to five years from metanephric blastema within the kidney; neuroblastoma arises in the adrenal medulla or sympathetic chain, with a median age under two years.
- Mass behaviour: a Wilms tumour is smooth, firm and unilateral — it displaces rather than crosses the midline; a neuroblastoma is irregular, fixed, notorious for crossing the midline and frequently calcified on imaging.
- Wilms associations: hypertension from renin, painless haematuria, and the syndromic links of aniridia, hemihypertrophy and genitourinary anomalies (WAGR, Beckwith-Wiedemann, WT1 on chromosome 11).
- Histology: Wilms is triphasic — blastemal, stromal and epithelial — and behaves well without anaplasia; neuroblastoma shows small round blue cells with Homer-Wright pseudorosettes, and N-myc amplification marks aggressive disease.
- Spread and markers: Wilms goes to lung, so chest imaging is mandatory; neuroblastoma goes to bone and orbits — raccoon eyes — and secretes vanillylmandelic and homovanillic acids in urine, with opsoclonus-myoclonus as a paraneoplastic syndrome.
- Wilms treatment is nephrectomy with vincristine and actinomycin-based chemotherapy, with doxorubicin and radiotherapy for higher stages, and cure rates are high for favourable histology; neuroblastoma treatment is risk-stratified, from surgery alone to intensive chemotherapy.
- Neuroblastoma stage 4S in infants with liver, skin or marrow involvement can regress spontaneously — an exam favourite.
Common confusion
The recurring stem is the midline: crossing predicts neuroblastoma, non-crossing Wilms — though exceptions exist and imaging decides. Calcification favours neuroblastoma, claw-signs of residual renal parenchyma on CT favour Wilms. Hypertension appears in both — renin in Wilms, catecholamines in neuroblastoma — so the separator is the urine vanillylmandelic acid, not the blood pressure. Finally, both present as abdominal masses in young children, so anchor on age and the catecholamine signature before answering.
Exam-focused takeaway
FMGE paediatric surgical oncology questions are matching questions: the three-to-five-year-old with a smooth flank mass, hypertension and lung metastasis is Wilms tumour treated by nephrectomy with vincristine and actinomycin-based chemotherapy; the infant with a fixed mass crossing the midline, calcification, raccoon eyes and high urinary vanillylmandelic acid is neuroblastoma treated by risk-stratified therapy. Learn WT1 on chromosome 11 and N-myc amplification, and the special situations of stage 4S regression and bilateral Wilms.
Frequently asked questions
Which tumour characteristically crosses the midline?
Neuroblastoma; a Wilms tumour is typically unilateral, smooth and confined, displacing rather than crossing.
What urinary marker is raised in neuroblastoma?
Vanillylmandelic acid with homovanillic acid, the catecholamine metabolites measured in urine.
What is the classic age for Wilms tumour?
Around three to five years, whereas neuroblastoma is generally a disease of children under five with a median in infancy.
What is triphasic histology?
The blastemal, epithelial and stromal elements of Wilms tumour; anaplasia marks the unfavourable subtype.
What is neuroblastoma stage 4S?
A special stage in infants with limited dissemination — liver, skin or bone marrow — that can regress spontaneously.
What chemotherapy anchors Wilms tumour treatment?
Vincristine and actinomycin D, with doxorubicin added for higher-stage disease, alongside nephrectomy.