Editing Pediatrics: Renal and Adrenal Oncology (section)

=== Staging ===
* '''<span style="color:#ff0000">Current staging system used by the Children’s Oncology Group (COG) is based primarily on the surgical and histopathologic findings (not imaging)'''

{| class="wikitable"
|Stage
| colspan="1" |
|-
| rowspan="1" |I
| colspan="1" rowspan="1" |
# Tumour limited to the kidney and completely resected
# Renal capsule intact
# The tumour was not ruptured or biopsied prior to removal
# Renal vein contains no tumour (intrarenal vessel involvement may be present)
# No residual tumour apparent beyond the margins of excision
|-
| rowspan="1" |II
| colspan="1" rowspan="1" |
# Tumour extends beyond the kidney but is completely resected
# Regional extension of tumour (vascular invasion outside the renal parenchyma or within the renal sinus and/or capsular penetration with negative excision margin)
# Operative tumour spill confined to flank (no peritoneal contamination)
# Tumour biopsy (except fine-needle aspiration) prior to surgery
|-
| rowspan="1" |III
| colspan="1" rowspan="1" |
# Non-haematogenous metastases confined to the abdomen (e.g., tumour in regional lymph nodes), including tumour implants on or penetrating the peritoneum
# Gross or microscopic tumour remains post-operative (tumour at the margins of resection)
# '''Tumour spill before or during surgery not confined to flank'''
# Piecemeal excision of the tumour (removal in >1 piece)
|-
| rowspan="1" |IV
| colspan="1" rowspan="1" |
# Presence of haematogenous metastases or metastases to distant lymph nodes
|-
| rowspan="1" |V
| colspan="1" rowspan="1" |
# Bilateral renal involvement at the time of initial diagnosis
|}


Source: Popov SD, Sebire NJ, Vujanic GM. Wilms’ Tumour – Histology and Differential Diagnosis. In: van den Heuvel-Eibrink MM, editor. Wilms Tumor [Internet]. Brisbane (AU): Codon Publications; 2016 Mar. Table 4. [COG staging system]. Available from: <nowiki>https://www.ncbi.nlm.nih.gov/books/NBK373364/table/tab1_4/</nowiki> doi: 10.15586/codon.wt.2016.ch1

* '''Any tumor spill leads to a stage III designation owing to the increased risk for local tumor recurrence'''