Wilms

• another common malignancy that almost always presents with abdominal swelling or the presence of an abdominal mass.
• Affected children frequently are otherwise well.
• Ultrasonography will identify a solid intrarenal mass.
• Involvement of the renal veins and inferior vena cava, as well as the contralateral kidney, should be noted.
• Median age of diagnosis is: 3 years (80% < 5 y/o)
• Abdominal or flank mass (large, smooth, firm, painless) - vs neuroblastoma -> nodular mass
  • Discovered while bathing/dressing
  • Rarely crosses midline (vs Neuroblastoma which crosses midline more often)
  • Some with pain or vomiting
• Bilateral in: 6-7%
• Hypertension (pressure on renal artery) 60%
• Hematuria (25%)
• Metastasis to: lungs, liver, bone or brain

Associations

• Chromosome 11 deletions: tumor-suppresor gene
• Omphalocele
• Genitourinary anomalies
• Hemihypertrophy (1000x increased risk)
• Aniridia (600X risk of Wilms’s, U/S q 3 mos till 4 y/o)
• WAGR: Wilms, Aniridia, GU malformations, Retardation
• Denys-Drash (Wilms, Nephropathy, MR, genital anomalies)
• for those with Beckwith-Wiedemann syndrome, risk of Wilm, so should be screened with abd US q 3-6 months until reach 6-8 yrs of age

Staging: National Wilms Tumor Study (NWTS)

• Stage 1: limited to kidney and completely excised (43% of patients)
• Stage 2: extends beyond kidney, but still completely excised
• Stage 3: residual tumor confined to abdomen
• Stage 4: hematogenous metastasis
• Stage 5: bilateral renal involvement

Treatment

• Nephrectomy
• Chemotherapy
• +/- Radiation (stages III, IV, & V)

Prognosis

• Stage 1&2 : >95% survival
• Stage 3 & 4: 90% survival

Neuroblastoma vs Wilms

• Presentation: NB- sicker, Wilms - incidental mass
• Age: NB younger (2 yo); Wilms older (3 yo)
• metastases: NB - Bone, BM, liver, orbit, skin, NOT lungs or brain; Wilms: Bone, Liver, lungs, brain   

Abdominal masses

CHLA Board Review 2005