What is the recommended presentation and treatment approach for a patient with suspected Wilms tumor?

Recommended Presentation and Treatment Approach for Suspected Wilms Tumor

Patients with suspected Wilms tumor should undergo immediate abdominal ultrasound followed by comprehensive cross-sectional imaging, with treatment involving a multidisciplinary approach of primary surgical resection followed by risk-stratified adjuvant chemotherapy with actinomycin D and other agents based on staging and histology. 1, 2

Diagnostic Approach

Initial Presentation

• Common presentations:
  • Abdominal mass (often painless)
  • Abdominal pain
  • Hematuria
  • Hypertension (due to renin production)
  • Fever (may indicate tumor-related inflammatory response or necrosis) 3

Diagnostic Workup

1. Imaging studies:

   • Abdominal ultrasound (first-line imaging)
   • CT scan or MRI of abdomen/pelvis (to assess tumor extent, bilateral involvement)
   • Chest imaging (to evaluate for metastatic disease)

2. Laboratory studies:

   • Complete blood count
   • Renal function tests
   • Urinalysis
   • Consider tumor lysis markers if large tumor burden 3

3. Genetic testing:

   • Indicated for all patients with bilateral Wilms tumors
   • Should include methylation and copy-number analysis of chromosome 11p15.5
   • Sequencing of WT1 and other predisposition genes (REST, TRIM28, DIS3L2, CTR9) 1
   • Particularly important for patients with epithelial-predominant histology (strong association with TRIM28 pathogenic variants) 1

Treatment Approach

Surgical Management

• Primary nephrectomy is the standard approach in North America 2, 4
  • Complete resection with lymph node sampling
  • Careful examination of contralateral kidney
  • Avoid tumor rupture during surgery (affects staging)
  • Preserve renal function when possible, especially in bilateral disease 5

Chemotherapy

• Adjuvant chemotherapy based on stage and histology:
  • Actinomycin D is a cornerstone of therapy (recommended dose: 45 mcg/kg IV once every 3-6 weeks for up to 26 weeks) 6
  • Often combined with vincristine for favorable histology
  • More intensive regimens including doxorubicin for higher-risk disease 2

Radiation Therapy

• Indicated for:
  • Higher stage disease (stage III and IV)
  • Unfavorable histology
  • Residual disease after surgery 2

Special Considerations

Bilateral Wilms Tumor

• Requires more complex management approach
• Nephron-sparing surgery when feasible
• Neoadjuvant chemotherapy often used to reduce tumor size before surgery
• More intensive surveillance recommended (abdominal ultrasounds every 3 months until at least 8 years of age) 1

Genetic Predisposition Syndromes

• Patients with identified predisposition syndromes require:
  • Genetic counseling
  • Cascade testing for first-degree family members
  • Ongoing surveillance with renal ultrasound every 3 months until at least 8 years of age 1

Management of Complications

• Fever management:
  • Complete blood count to assess for neutropenia
  • Blood cultures from all central line lumens
  • Empiric antibiotics for neutropenic fever
  • Consider tumor lysis syndrome as potential cause 3

Treatment Outcomes and Follow-up

• Five-year survival exceeds 90% for favorable histology with appropriate treatment 2
• Long-term follow-up needed to monitor for:
  • Renal function
  • Cardiomyopathy (from anthracycline therapy)
  • Secondary malignancies
  • Recurrence 4

Pitfalls to Avoid

1. Delayed diagnosis - Any child with an abdominal mass should prompt immediate imaging
2. Tumor rupture during surgery (increases stage and treatment intensity)
3. Missing bilateral disease - thorough examination of contralateral kidney essential
4. Inadequate genetic evaluation - particularly important for bilateral disease and patients with epithelial-predominant histology
5. Failure to involve pediatric oncology - all patients should be managed by a multidisciplinary team with experience in pediatric renal tumors 2