para>WAGR (Wilms tumor, aniridia, genitourinary abnormalities, mental retardation)
Beckwith-Wiedemann syndrome (macroglossia, omphalocele, visceromegaly, hemihypertrophy)
Denys-Drash syndrome (ambiguous genitalia, progressive renal failure, and increased risk of Wilms tumor)
Diagnosis
History
- Abdominal distention
- Abdominal pain (20 " 30% of cases)
- Hematuria (20 " 30% of cases)
- Fever, anorexia, vomiting
- Family history of Wilms tumor
- Rapid increase in abdominal size (suggestive of hemorrhage in the tumor)
Physical Exam
- Asymptomatic abdominal mass extending from flank toward midline (most common presentation)
- Anemia (secondary to hemorrhage in the tumor)
- Fever
- Hypertension (owing to increased renin production in 25% of cases)
- Varicocele (indicates obstruction to spermatic vein owing to tumor thrombus in renal vein or inferior vena cava)
- Aniridia, hemihypertrophy, cryptorchidism, hypospadias
- Signs of Beckwith-Wiedemann and neurofibromatosis
Diagnostic Tests & Interpretation
Lab
- CBC
- Electrolytes
- Urine analysis: for microscopic hematuria
- Liver and kidney function tests
- Coagulation factors
Imaging
- Ultrasound of abdomen
- Diagnostic of mass of renal origin
- Evaluate for extension of tumor into inferior vena cava.
- CT scan of abdomen, chest radiograph, and chest CT: to evaluate for metastatic disease
- Bone scan: only if clear cell sarcoma, renal cell carcinoma, or rhabdoid tumor on pathology
- MRI of head: only for clear cell sarcoma and rhabdoid tumors
- EKG and echocardiogram in patients who will receive anthracycline chemotherapy
Pathologic Findings
- Gross pathology
- Often cystic with hemorrhages and necrosis
- Usually no calcification (useful in differentiating from neuroblastoma, which is calcified on plain radiograph)
- May extend into the inferior vena cava
- Histology
- Triphasic pattern blastemal, epithelial, and stromal cell
- Blastemal cells aggregate into nodules like primitive glomeruli; the presence of diffuse anaplasia indicates a poor prognosis.
- Clinicopathologic staging
- Stage I: Tumor is restricted to one kidney and completely resected. The renal capsule is intact.
- Stage II: Tumor extends beyond the kidney but is completely excised.
- Stage III: Residual nonhematogenous tumor is confined to the abdomen.
- Stage IV: There is hematogenous spread to lungs, liver, bone, or brain.
- Stage V: Bilateral disease
Differential Diagnosis
- Polycystic kidney
- Renal hematoma
- Renal abscess
- Neuroblastoma
- Other neoplasms of kidney: clear cell carcinoma, rhabdoid tumor
Alert
Rarely, Wilms tumor may present with polycythemia. It can present as fever of unknown origin without any other signs or symptoms.
Treatment
Special Therapy
Radiotherapy
- Not required for stage I and II patients unless anaplastic, clear cell, or rhabdoid
- Radiotherapy to tumor bed with 1,080 cGy for stages III and IV. If gross tumor spillage or peritoneal seeding, treat whole abdomen
- Whole-lung radiation (1,200 cGy) for pulmonary metastasis
Medication
- Chemotherapy
- For stages I and II favorable histology: vincristine and actinomycin D every 3 weeks for 6 months
- For stages III and IV favorable histology, stage I " III focal anaplasia, and stage I diffuse anaplasia: vincristine, actinomycin D, and doxorubicin for 6 " 15 months
- Add cyclophosphamide and/or etoposide for higher stage anaplastic tumors (stage IV focal or II " IV diffuse).
- Side effects of therapy
- Temporary loss of hair
- Peripheral neuropathy
- Impaired function of the remaining kidney over years following radiation
- Cardiac toxicity with doxorubicin
- Second malignant neoplasms in few cases
Surgery/Other Procedures
- Nephrectomy
- Preoperative chemotherapy in case of very large tumors with inferior vena cava extension
- For bilateral disease, nephrectomy of more affected side and partial nephrectomy of the other side, followed by chemotherapy and radiation
Ongoing Care
Prognosis
- Stages I and II: >90% cured
- Stage III: 85% cured
- Stage IV: 70% cured
- Favorable prognostic factors
- Tumor weight <250 g
- Age at presentation <24 months
- Stage I disease
- Favorable histology
- Poor prognostic factors
- Diffuse anaplastic pathology
- Clear cell sarcoma variant
- Rhabdoid tumor variant
- Lymph node involvement
- Distant metastasis
- Tumors with loss of heterozygosity (LOH) of chromosomes 1p and/or 16q
Complications
- Extension into inferior vena cava
- Metastasis to lungs and liver
- Cardiac toxicity secondary to doxorubicin
- Liver dysfunction secondary to actinomycin D and radiation therapy
Follow-up Recommendations
Patient Monitoring
- Every 3 months for 18 months, every 6 months for 1 year, and then yearly
- Chest radiograph, urinalysis, and abdominal ultrasound at regular intervals
Additional Reading
- Blakely ML, Ritchey ML. Controversies in the management of Wilms ' tumor. Semin Pediatr Surg. 2001;10(3):127 " 131. [View Abstract]
- Davidoff AM. Wilms tumor. Adv Pediatr. 2012; 59(1):247 " 267. [View Abstract]
- Hohenstein P, Hastie ND. The many facets of the Wilms ' tumour gene, WT1. Hum Mol Genet. 2006;15(Spec No 2):R196 " R201. [View Abstract]
- Martinez CH, Dave S, Izawa J. Wilms ' tumor. Adv Exp Med Biol. 2010;685:196 " 209. [View Abstract]
- McLean TW, Buckley KS. Pediatric genitourinary tumors. Curr Opin Oncol. 2010;22(3):268 " 273. [View Abstract]
Codes
ICD09
- 189.0 Malignant neoplasm of kidney, except pelvis
ICD10
- C64.9 Malignant neoplasm of unsp kidney, except renal pelvis
- C64.1 Malignant neoplasm of right kidney, except renal pelvis
- C64.2 Malignant neoplasm of left kidney, except renal pelvis
SNOMED
- 302849000 Nephroblastoma (disorder)
FAQ
- Q: What should be done to protect the remaining kidney during sports?
- A: Children should wear a kidney guard to protect the unaffected kidney during contact sports.
- Q: Can a child grow and live normally with 1 kidney?
- A: Yes.