This is the most common intra-abdominal tumour of childhood (20% of all childhood malignancies). It is an undifferentiated mesodermal tumour of the intermediate cell mass (primitive renal tubules and mesenchymal cells). It may be sporadic or familial.
- Wilms' tumour is the second most common intraabdominal cancer of childhood and the fifth most common paediatric malignancy overall (approximately 6% of all paediatric cancers).
- Only 3% of Wilms' tumours are reported in adults. Most adult patients are diagnosed unexpectedly following nephrectomy for presumed renal cell carcinoma.
- In 5-10% of patients, both kidneys are affected at the same time (synchronous bilateral Wilms' tumour) or one after the other (metachronous bilateral Wilms' tumour).
Wilms' tumours usually develop in otherwise healthy children, but approximately 10% occur in children with recognised malformations; either:
- 'Overgrowth syndromes' (excessive prenatal and postnatal somatic growth resulting in macroglossia, nephromegaly, and hemihypertrophy) - most commonly, Beckwith-Wiedemann syndrome or isolated hemihypertrophy. Others include Perlman syndrome, Sotos' syndrome, and Simpson-Golabi-Behmel syndrome.
- No 'overgrowth' - associated with trisomy 18, Bloom's syndrome, Denys-Drash syndrome; or Wilms' with Aniridia, Gonadoblastoma (GU malformations), and Retardation (WAGR).
Familial Wilms' tumour
Hereditary Wilms' tumour (either bilateral tumours or a family history of the neoplasm) is uncommon. Several different families with Wilms' tumours have been identified. All are transmitted in an autosomal dominant manner, caused by mutations in one of at least three genes:
- One related to the WT1 gene on chromosome 11 (11p13) - (includes those patients with WAGR) - encodes a protein which is a transcriptional repressor downregulating IGF-II, an insulin-like growth factor.
- Other families (including those with Beckwith-Wiedemann syndrome) have a different mutation - of the WT2 gene on chromosome 11 (11p15.5).
- Other gene mutations, thought to be on chromosome 16 (WT3-16q) and/or chromosome 1p can also cause the tumour.
95% are unilateral. Only 1-2% have a positive family history.
- The most common presentation is an asymptomatic abdominal mass.
- Abdominal pain.
- Urinary tract infection.
- Hypertension, gross haematuria and fever may occur but are uncommon.
- Advanced disease may rarely present with respiratory symptoms due to lung metastases.
A recommendation for surveillance of children at high risk included:
- Surveillance should only be offered after review by a clinical geneticist.
- Surveillance should be carried out by renal ultrasound every 3-4 months.
- Surveillance should continue until 5 years of age in all conditions except Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome and some familial Wilms' tumour pedigrees, when it should continue until 7 years.
- Useful laboratory tests include FBC, renal function and electrolytes, and urinalysis.
- Genetic studies may reveal the chromosomal abnormalities consistent with the condition.
- Ultrasound and/or intravenous pyelogram (IVP) may show distortion of the renal pelvis; hydronephrosis. Dynamic imaging of the renal vein and inferior vena cava may be contributory.
- Renal angiography may help to show a more detailed view of the blood vessels.
- CT and MRI scanning may help to determine the nature of the tumour and may also reveal the degree of involvement of the lymph nodes, whether the other kidney is involved, and invasion into blood vessels or the liver.
- Transcutaneous renal biopsy should be avoided, as this may make the condition worse.
- Chest CT to detect lung metastases.
|Staging of Wilms' tumour|
|Stage I (43% of patients)||Tumour limited to the kidney and completely excised. Renal capsule is intact.
The tumour is not ruptured before or during removal.
The vessels of the renal sinus are not involved.
There is no residual tumour apparent beyond the margins of excision.
|Stage II (23% of patients)||Tumour extends beyond the kidney but is completely excised. No residual tumour is apparent at or beyond the margins of excision.
There may be:
|Stage III (23% of patients)||There is residual tumour confined to the abdomen. There may be one or more of the following:
|Stage IV (10% of patients)||Haematogenous metastases - beyond stage III - eg, to the lung, liver, bone, or brain.|
|Stage V (5% of patients)||Bilateral renal involvement at initial diagnosis. Attempt to stage each side according to the above criteria on the basis of extent of disease prior to biopsy.
Four-year survival was 94% for those patients whose most advanced lesion was stage I-II; 76% where it was stage III.
- For most patients, nephrectomy followed by chemotherapy (regimes include vincristine, dactinomycin and doxorubicin) can be curative.
- Radiotherapy to the flank is beneficial in patients with a stage III tumour.
- Patients with massive, nonresectable unilateral tumours, bilateral tumours, or venacaval tumour thrombus above the hepatic veins should be considered for preoperative chemotherapy because of the risk of initial surgical resection.
- With treatment, over 80% of children diagnosed with Wilms' tumour survive long-term.
- There is an increased risk of second tumours in survivors of Wilms' tumour. Second tumours include bone and soft-tissue sarcomas, breast cancer, lymphoma, gastrointestinal tumours and melanoma. Acute leukaemias may also occur.
Further reading & references
- Davidoff AM; Wilms tumor. Adv Pediatr. 2012;59(1):247-67. doi: 10.1016/j.yapd.2012.04.001.
- Ali EM, Elnashar AT; Adult Wilms' tumor: review of literature. J Oncol Pharm Pract. 2012 Mar;18(1):148-51. doi: 10.1177/1078155210396264. Epub 2011 Jan 19.
- Segers H, van den Heuvel-Eibrink MM, Pritchard-Jones K, et al; Management of adults with Wilms' tumor: recommendations based on international consensus. Expert Rev Anticancer Ther. 2011 Jul;11(7):1105-13. doi: 10.1586/era.11.76.
- Wilm's Tumor 1, WT1; Online Mendelian Inheritance In Man (OMIM)
- Wilms Tumor 3, WT3; Online Mendelian Inheritance in Man (OMIM)
- Kraemer KH. Xeroderma Pigmentosum. In: Gene Reviews, updated May 2008. (Detailed overview of xerorderma pigmentosum)
- Scott RH, Walker L, Olsen OE, et al; Surveillance for Wilms tumour in at-risk children: pragmatic recommendations for best practice. Arch Dis Child. 2006 Dec;91(12):995-9. Epub 2006 Jul 20.
- Wilms Tumor and Other Childhood Kidney Tumors; US National Cancer Institute
- Levitt G; Renal tumours: long-term outcome. Pediatr Nephrol. 2012 Jun;27(6):911-6. doi: 10.1007/s00467-011-1998-3. Epub 2011 Sep 27.
|Original Author: Dr Laurence Knott||Current Version: Dr Colin Tidy||Peer Reviewer: Dr Helen Huins|
|Last Checked: 28/03/2013||Document ID: 2938 Version: 22||© EMIS|
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