📋 MOCK OSCE · FCPS, MCPS, MD PAEDIATRICS ⏱ 10 min · ABDOMINAL MASS (NEUROBLASTOMA)

Neuroblastoma · Short Case

Candidate task: perform focused clinical examination (GPE + abdomen) on a child with suspected neuroblastoma.
Then discuss differential diagnosis, investigations, management & follow‑up.
Pre‑exam Protocol
⏤ · Wash, Warm, Introduce, Position, Expose, Approach ▾

Standard pre‑examination protocol – must be demonstrated:

🖐 Wash hands with sterilizing solution.
🔥 Warm hands and stethoscope.
👋 Introduce yourself to child & parent.
🧍 Position child: standing → sitting → supine.
👕 Exposure — shirt off, trousers rolled.
➡️ Approach from the right side.
✔ CPSP marker: Pre‑exam Protocol is observed and scored.
1. Clinical Examination (≈6 min)
02 General Look (Inspection from end of bed) ▾

Key observations:

  • Abdomen: asymmetrical bulging, often crosses midline; may be firm, irregular.
  • Periorbital ecchymosis – “raccoon eyes” (retro-orbital metastases).
  • Skin: bluish subcutaneous nodules (“blueberry muffin” in infants).
  • Opsoclonus-myoclonus – dancing eyes, jerky movements (paraneoplastic).
  • Horner syndrome – ptosis, miosis, anhydrosis (cervical primary).
  • Nutritional status: may be cachectic in advanced disease.
👁 Red flags: periorbital ecchymosis + opsoclonus + midline abdominal mass → neuroblastoma.
03 General Physical Exam (Hands → Face → Chest → Limbs) ▾

Systematic examination:

  • Hands: clubbing (rare), pallor (anaemia).
  • Face: periorbital ecchymosis, proptosis, Horner syndrome (ptosis/miosis).
  • Chest: signs of mediastinal mass (dullness, stridor, superior vena cava syndrome).
  • Abdomen: see next step.
  • Lower limbs: bone pain (metastases), limping, hypertension (renal artery compression).
📏 Anthropometry: weight, height, BMI – plot growth.
04 Abdominal Examination ▾

Systematic approach:

  • Inspection: asymmetrical distension, visible mass (often crosses midline).
  • Auscultation: bowel sounds (normal/obstructive), bruits (vascular – rare).
  • Palpation: firm, irregular, non-tender mass; crosses midline (unlike Wilms). May be fixed (retroperitoneal).
  • Percussion: dull over mass.
  • Rectal: if indicated – pelvic extension (sacrococcygeal teratoma in differential).
🔍 Key: midline-crossing, irregular, fixed abdominal mass + periorbital ecchymosis → neuroblastoma.
05 Developmental Assessment & Associated Signs ▾

Assess:

  • Neurological: opsoclonus-myoclonus-ataxia (paraneoplastic), motor weakness (spinal cord compression).
  • Eyes: periorbital ecchymosis, proptosis, Horner syndrome.
  • Chest: respiratory distress (mediastinal mass).
  • Growth: may be normal or delayed.
🧠 Opsoclonus-myoclonus: dancing eyes + jerky movements → paraneoplastic neuroblastoma (often good prognosis).

📋 Case Presentation – (fill in during exam)

This is a _____-year-old _____ child, brought with _____ (abdominal swelling / periorbital ecchymosis / opsoclonus). On examination, the child appears _____ (well/unwell), with _____ (periorbital ecchymosis / Horner syndrome / opsoclonus). There is a _____ (firm / irregular / non-tender) mass in the _____ (abdomen/flank), measuring approximately _____ cm. The mass _____ (does / does not) cross the midline, and _____ (is / is not) fixed. Growth parameters: weight _____ percentile, height _____ percentile. Additional findings: _____ (periorbital ecchymosis / opsoclonus / hypertension / Horner syndrome).

2. Viva Discussion (≈4 min)
06 Viva · Differential, Investigations, Management, Follow‑up ▾
🔹 Differential Diagnosis

• Neuroblastoma – adrenal/retroperitoneal, crosses midline, calcifications, catecholamines
• Wilms tumor – renal, does NOT cross midline, haematuria
• Mesoblastic nephroma – neonatal, benign
• Clear cell sarcoma of kidney – aggressive, bone metastases
• Rhabdoid tumor of kidney – aggressive, young infants
• Non-Hodgkin lymphoma – bilateral, rapid, B symptoms
• Hepatoblastoma – right upper quadrant, AFP elevated
• Germ cell tumor (sacrococcygeal) – pelvic/sacral
• Ganglioneuroma – benign form of neuroblastoma
• Hydronephrosis – cystic, fluctuant
• Polycystic kidney disease – bilateral, family history

🔹 Investigations – Diagnosis

• Urinary catecholamines – VMA & HVA (elevated in >90%)
• Abdominal US/CT/MRI – defines mass, calcification, encasement
• MIBG scan – ¹²³I-MIBG; sensitive for neuroblastoma (90%)
• Bone marrow biopsy – staging (metastases)
• Chest CT – lung metastases (less common)
• Bone scan – cortical bone metastases
• Serum LDH, ferritin, NSE – prognostic markers
• MYCN amplification – FISH/PCR; poor prognosis

🔹 Investigations – Aetiology

• MYCN amplification – poor prognosis (high-risk)
• ALK gene – familial neuroblastoma
• PHOX2B – associated with Hirschsprung, central hypoventilation
• Ploidy – hyperdiploid (good prognosis in infants)
• 1p, 11q LOH – poor prognosis
• ATRX, TERT – mutations in high-risk disease
• TrkA, TrkB – nerve growth factor receptors; expression correlates with outcome

🔹 Investigations – Exclude Others

• AFP, β-hCG – exclude hepatoblastoma/germ cell
• Urine microscopy – haematuria (exclude Wilms)
• Chest X-ray – mediastinal mass
• LDH – may be elevated in aggressive disease
• Platelet count – thrombocytopenia (bone marrow infiltration)
• Serum electrolytes – SIADH (if intracranial involvement)

🔹 Investigations – Rule Out Complications

• Spinal cord compression – MRI spine (urgent)
• Hypertension – renal artery compression; BP monitoring
• Superior vena cava syndrome – mediastinal mass; chest CT
• Bone metastases – MIBG, bone scan, bone marrow
• Opsoclonus-myoclonus – neurological exam; usually no specific imaging
• Secretory diarrhea – VIP secretion; electrolyte monitoring

🔹 Management – Across Organ Systems

Surgical

Complete resection (if possible) – goal >90% tumour removal. For high-risk, biopsy + neoadjuvant chemotherapy before delayed resection.

Chemotherapy

Risk-adapted: Low-risk: observation/surgery alone. High-risk: induction (cisplatin, etoposide, cyclophosphamide, doxorubicin, vincristine), high-dose chemotherapy with stem cell rescue.

Radiotherapy

Focal radiation to primary tumour and metastatic sites (high-risk). MIBG therapy (¹³¹I-MIBG) for refractory disease.

Immunotherapy

Anti-GD2 monoclonal antibody (dinutuximab) + GM-CSF + IL-2 for high-risk post-transplant maintenance.

Differentiation

13-cis-retinoic acid (isotretinoin) – promotes neuronal differentiation; given post-transplant.

Hypertension

ACE inhibitors (captopril, enalapril) or calcium channel blockers. Monitor BP.

Supportive Care

Transfusions (PRBC, platelets) for cytopenias. G-CSF for neutropenia. Anti-emetics, pain management.

Spinal Cord Compression

Urgent corticosteroids, chemotherapy/radiotherapy, surgical decompression.

📈 Prognosis

  • Low-risk: 5-yr OS >95%.
  • Intermediate-risk: 5-yr OS ~90–95%.
  • High-risk (no MYCN): 5-yr OS ~50–60%.
  • High-risk (MYCN amp): 5-yr OS ~30–40% (with modern therapy).
  • Stage 4S (MS): excellent (>90%) – may regress spontaneously.
  • Age <18 months: generally better prognosis.
  • Opsoclonus-myoclonus: good prognosis (often low-risk).

📋 Follow‑up Schedule

  • During treatment: weekly CBC, LFTs, renal function; BP monitoring.
  • After treatment (first 2 yr): MIBG, urine catecholamines, imaging every 3–6 months.
  • Years 2–5: imaging and markers every 6–12 months.
  • Late effects screening: hearing loss (cisplatin), renal function (cisplatin), cardiac (anthracyclines), secondary malignancies.
  • Genetic counselling: for familial cases (ALK, PHOX2B).
💡 Examiner expectation: logical differential (neuroblastoma vs Wilms vs others), systematic investigation (diagnosis → aetiology → exclude others → complications), and a management plan covering risk-adapted therapy. Know the INRG staging system and MYCN amplification significance.
📚 Visit paeds.online for more CPSP resources
Mock OSCE · Neuroblastoma (Abdominal Mass) · Based on Wyne‑Harris, Nelson & Pediatric Clinical Advisor