Wilms tumor

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Wilms Tumor - The Kidney Culprit

  • Most common renal malignancy in children, peaking at age 2-5 years.
  • Typically presents as a painless, unilateral abdominal mass found by a parent. May have hematuria or hypertension.
  • Associated with syndromes: WAGR, Denys-Drash, Beckwith-Wiedemann.
  • Classic histology is triphasic: blastemal, epithelial, and stromal elements.

⭐ Look for aniridia (absent iris) - it strongly suggests WAGR syndrome (Wilms, Aniridia, Genitourinary anomalies, Retardation).

Triphasic Wilms Tumor Histopathology

  • WT1 Gene (11p13): Tumor suppressor gene deletion/mutation.

    • WAGR Syndrome: 📌 Wilms tumor, Aniridia, Genitourinary anomalies, mental Retardation.
    • Denys-Drash Syndrome (DDS): Wilms tumor, diffuse mesangial sclerosis → early renal failure, male pseudohermaphroditism.
  • WT2 Gene (11p15): Abnormal imprinting.

    • Beckwith-Wiedemann Syndrome (BWS):
      • Hemihypertrophy, macroglossia, omphalocele, neonatal hypoglycemia.
      • Increased risk of hepatoblastoma & neuroblastoma.
      • ⭐ BWS is associated with ↑ risk of embryonal tumors, not just Wilms.

Clinical features of Beckwith-Wiedemann Syndrome

Clues & Confirmation - The Workup

  • Initial Test: Abdominal Ultrasound
    • Differentiates cystic vs. solid mass.
    • Assesses contralateral kidney & IVC for thrombus.
  • Investigation of Choice: CECT Abdomen & Pelvis
    • Shows intra-renal origin (📌 Claw Sign).
    • Stages the tumor, checks nodes, and vascular invasion.
  • Metastasis Screen: CT Chest (Lungs are #1 site).
  • Definitive Diagnosis: Histopathology (Post-nephrectomy or pre-chemo biopsy).
  • Labs: Urinalysis (hematuria), renal function tests. Genetic testing if syndromes suspected (e.g., WAGR).

CECT Finding: The "claw sign" - sharp angles formed by the tumor and normal renal parenchyma - confirms the intra-renal origin of the mass.

Wilms Tumor vs Neuroblastoma CT: Claw Sign

Staging & Story - Favorable vs. Foe

Based on the NWTS/COG staging system. Histology is the most critical prognostic factor, dividing tumors into two main stories.

  • Favorable Histology: Found in ~95% of cases. Shows classic triphasic pattern (blastemal, epithelial, stromal) and has an excellent prognosis.
  • Anaplastic Histology (Foe): Found in ~5%. Marked by extreme nuclear atypia (anaplasia) and linked to TP53 mutations. Carries a significantly poorer prognosis.

Lungs are the most common site for hematogenous metastasis in Wilms tumor.

The Takedown - Treatment Triumphs

  • Primary Goal: Complete tumor removal and prevention of recurrence using a multimodal strategy.
  • Surgery: Radical nephrectomy with lymph node sampling is standard.
  • Chemotherapy (Stage-Dependent):
      • Low Risk (Stage I/II, FH): Vincristine + Actinomycin-D.
      • High Risk (Stage III/IV, FH): Add Doxorubicin (VAD) ± Radiotherapy.
      • Anaplastic: Requires intensified chemotherapy.

SIOP vs. NWTSG: Key protocol difference. SIOP (Europe) uses pre-operative chemotherapy to downstage tumors before surgery. NWTSG (USA) proceeds with upfront surgery followed by chemotherapy.

  • Most common renal tumor of childhood, typically presenting at 2-5 years.
  • Associated with syndromes like WAGR, Denys-Drash, and Beckwith-Wiedemann.
  • Presents as a painless, palpable abdominal mass that does not cross the midline.
  • Do NOT palpate the abdomen deeply to prevent tumor rupture and spillage.
  • Histology is classically triphasic: blastemal, epithelial, and stromal elements.
  • Anaplasia is the single most important unfavorable prognostic factor.

Practice Questions: Wilms tumor

Test your understanding with these related questions

A 63-year-old man presents with a 2-month history of increasing sensation of fullness involving his left flank. The patient reports recent episodes of constant pain. The patient is hypertensive (145/90 mm Hg) and is currently on medications including losartan and hydrochlorothiazide. His past medical history is otherwise unremarkable. He is a 30-pack-year smoker. His temperature is 37.7°C (99.9°F); pulse, 76/min; and respiratory rate, 14/min. Palpation of the left flank shows a 10 x 10-cm mass. The patient's laboratory parameters are as follows: Blood Hemoglobin 19.5 g/dL Leukocyte count 5,000/mm3 Platelet count 250,000/mm3 Urine Blood 2+ Protein negative RBC 45/hpf without dysmorphic features Abdominal CT scan confirms the presence of a large solid mass originating in the left kidney. These findings are most consistent with which of the following conditions?

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Flashcards: Wilms tumor

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Canakinumab can be used to treat patients with Systemic _____ Arthritis

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Canakinumab can be used to treat patients with Systemic _____ Arthritis

Juvenile Idiopathic

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