Diagnosis

History

Presenting Complaint

Most patients present with no specific symptoms. Parents or children usually notice an abdominal mass incidentally. About one third of patients have other symptoms, usually fevers, weight loss, haematuria, anorexia, nausea or vomiting. Patients with metastatic disease may present with symptoms related to metastases.

Past History

A past history of congenital abnormalities should be elicited. The commonly associated findings include aniridia, mental retardation, or genitourinary malformations. The three common congenital syndromes are:

  • WAGR syndrome (Wilms Tumour, Aniridia, Genitourinary malformations and mental Retardation), due to deletion of the WT1 gene on chromosome 11
  • Beckwith-Wiedermann Syndrome, due to errors in a gene locus on chromosome 11 (not WT1)
  • Denys-Drash Syndrome, due to a point mutation in WT1

Medications

Nil specific

Allergies

Nil specific

Family History

Family history of malignancy syndromes (eg. Li Fraumeni) may be related to the development of nephroblastoma.

Social History

The child's ability to attend treatment and social supports should be elicited.


Examination

Examination should focus on:

  • Extent of local disease
  • Presence of metastatic disease
  • Detection of the presence of underlying syndromes (WAGR/Denys-Drash/Beckwith-Wiedermann)

Hypertension and haematuria are not uncommon findings. Coagulopathy is uncommon


Imaging

Abdominal ultrasound is a good first investigation. It allows:

  • Determination of origin of abdominal mass
  • Presence of renal obstruction
  • Presence and status of contralateral kidney
  • Imaging with non-ionising radiation

CT of the abdomen is also useful in identifying the extent of local disease and the presence of local metastases or bilateral nephroblastoma. MRI may also play a role. The staging of the contralateral kidney is controversial - some argue that imaging alone is sufficient whereas others insist that the contralateral kidney must be surgically explored during treatment of the definitely involved kidney. Also controversial is the use of CT to determine the presence of pulmonary metastases (versus plain chest X-ray).


Histological Diagnosis

The histological diagnosis of nephroblastoma is controversial.

  • SIOP recommends neoadjuvant therapy with chemotherapy and/or radiotherapy to downstage the tumour and reduce the risk of tumour spillage.
  • COG recommends initial surgical excision followed by adjuvant treatments as required

The ideal method has not yet been determined. Proponents of the SIOP method believe that neo-adjuvant treatment allows for reduced tumour spillage and reduced surgical morbidity due to smaller operations. Opponents say that SIOP can render diagnosis of the tumour difficult, and also claim that up to 5-6% of patients are treated for benign or non-nephroblastoma conditions.


Staging

Staging varies depending on the organisation (SIOP and COG).

SIOP Staging

Stage Description
I Completely resected; tumour is limited to the kidney; or if beyond the kidney
the tumour is confined by the pseudocapsule
II Completely resected; tumour directly invades adjacent structures such
the IVC, adrenal glands or pancreas etc.
III Incompletely excised tumour, due to
* Involvement of surgical margins
* Involvement of abdominal lymph nodes
* Peritoneal contamination by tumour or intraoperatively
* Residual abdominal tumour
* Non-contigous resection / piecemeal resection
* Biopsy of tumour prior to neoadjuvant chemotherapy
* Presence of necrotic tumour or chemotherapy changes in margins or nodes
IV Haematogenous or non-abdominal lymph node metastases
V Bilateral tumours; each tumour should be sub-staged as above

COG Staging

Stage Description
I Completely resected; tumour is limited to the kidney and
the renal capsule is intact
II Completely resected; tumour directly invades adjacent structures such
the IVC, adrenal glands or pancreas etc.
III Incompletely excised tumour, due to
* Involvement of surgical margins
* Involvement of abdominal lymph nodes
* Peritoneal contamination by tumour or intraoperatively
* Residual abdominal tumour
* Non-contigous resection / piecemeal resection
IV Haematogenous or non-abdominal lymph node metastases
V Bilateral tumours; each tumour should be sub-staged as above

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