Wilms' tumor, or nephroblastoma, is the most common renal tumor in children aged 2 to 4, typically presenting as an asymptomatic abdominal mass. The overall survival rate is 85% due to advancements in diagnosis and treatment, with approaches varying between different organizations like the Children Oncology Group and the International Society of Pediatric Oncology. Diagnosis and staging involve various imaging techniques, and treatment typically includes nephrectomy followed by chemotherapy and/or radiotherapy, depending on the disease stage and histology.

1. WILMS’ TUMOUR
PEDIATRIC SURGERY
AN OVRVIEWDr.B.Selvaraj MS;Mch;FICS;
“Surgical Educator”
Malaysia

2. WILMS’ TUMOUR
Objectives
 Overview
 Epidemiology & Etiology
 Pathology
 Clinical features
 Investigations
 Staging
 Differential Diagnosis
 Treatment

3. WILMS’ TUMOUR- Overview
 Wilms’ tumour (WT) or Nephroblastoma
is the most common renal tumour
affecting children of 2 to 4 yrs old
 Presents as an asymptomatic abdominal
mass in children.
 Most Wilms’ tumours are unilateral,
being bilateral in < 5 % of cases.
 Overall survival rate is 85% because of
multidisciplinary treatment.
 Advancements in the diagnosis and
treatment of Wilms' tumour have
greatly improved the prognosis for
children with this disease.
 Two study groups are instrumental in
establishing the basis for current
therapy:
- The Children Oncology Group(COG)
previously National Wilms’ Tumour
Study Group (NWTSG) in North America
-The International Society of
Paediatric Oncology (SIOP) in Europe
 Immediate nephrectomy is the
preferred approach of the COG,
whereas in SIOP, nephrectomy follows
a short course of chemotherapy.

4. WILMS’ TUMOUR- Etiology
 Incidence seven in a million children in the
USA. 6% 0f all renal tumour in children
 Black children more affected than others.
 Girls are more prone to develop than boys.
 Risk factors are African-American race and
family H/O Wilms’ tumour.
 75 % of Wilms tumour occurs in healthy
children; but in 25 % cases, is associated with
other genetic abnormalities
 Beckwith–Wiedemann syndrome consists of
Omphalocele, Macroglossia and
Visceromegaly
 Denys–Drash syndrome consists of Wilms
tumor,Kidney disease and Male
pseudohermaphroditism.
 WAGR syndrome consists of Wilms tumor,
Aniridia, Genital abnormalities and Mental
retardation
 WT1 is the Wilms’ tumor suppressor gene
located at chromosome 11pl3. The gene is
deleted in WAGR syndrome and has point
mutations in Denys-Drash syndrome.
 Beckwith–Wiedemann syndrome is associated
with loss of heterozygosity (LOH) at
chromosome 11p15, and the WT2 gene may be
situated at this locus.

5. WILMS’ TUMOUR- Pathology
 Grossly, Wilms tumor is a large, solitary, and
well-circumscribed mass with the remaining
rim of normal kidney tissue.
 On cut section, Wilms tumor is soft,
homogenous, and tan-gray in color and may
contain areas of hemorrhage and necrosis
 Pathologically, origin of the tumor is the
metanephric blastema- composed of three
elements blastemal, stromal and epithelial .
 Pathologically, Wilms tumours are divided
into two prognostic groups:
 Favorable: Contains well-developed
components.
 Unfavorable (Anaplastic): Contains
anaplastic cells, which could be focal or
diffuse.
 Typical appearance of the tumour consisting of
solid and cystic parts as well as hemorrhagic
regions

6. WILMS’ TUMOUR- Clinical Features
 Abdominal mass- normally won’t cross
midline- 75%
 Haematuria- Gross-18%, Micro-24%
 Hypertension- 26%
 Abdominal pain- 28%
 Fever- 22%
 Pulmonary metastases (15% of cases)
 Involvement of renal vein, inferior
vena cava (IVC involved in 8% of cases)
or atrium
 Patients with a genetic predisposition
to Wilms tumor, such as Beckwith-
Wiedemann syndrome,WAGR
syndrome, or Denys-Drash syndrome.

7. WILMS’ TUMOUR-Investigations
 The aim is to evaluate the site, size, and extent
of the tumour, the presence or absence of
secondaries and kidney functioning status
 A plain abdominal radiograph often shows
displacement of abdominal organs and
occasionally the presence of calcification (< 10
%) at edge of tumour.
 Abdominal ultrasound confirms that the kidney
is the site of the tumour, determines whether
the mass is a cystic or solid tumour, and
indicates if the tumour extends into the renal
veins and inferior vena cava.

8. WILMS’ TUMOUR-Investigations
 CT scan defines the Wilms tumor site;
identifies the presence of enlarged lymph
nodes; evaluates the possible presence of a
second Wilms tumor in the opposite kidney;
assesses involvement of the tumor into the
renal veins, inferior vena cava, and right
atrium
 Determines if the patient has intra-abdominal
secondaries to the liver.
Showing a large
leftsided Wilms
tumor. Note the
thin rim of
remaining kidney-
‘Claw Sign’
CT bilateral
Wilms' tumour

9. WILMS’ TUMOUR-Investigations
 MRI- Coronal view- Lt Wilms'
tumour
 T1 hypointense, T2
mixed/hyperintense
 Useful in assessing bilateral
disease, vascular involvement
and nephroblastomatosis

10. WILMS’ TUMOUR-Investigations
 In 25–40% of WT patients,
additional abnormal cell clusters
can be found within normal parts
of the kidney, the so-called
nephrogenic rests (NR)
 Rarely both kidneys consist of
diffuse nephrogenic rests—a
pathology that is called
nephroblastomatosis.

11. WILMS’ TUMOUR- Staging
Staging system utilized by
the Children Oncology Group
(National Wilms’ Tumor
Study Group- NWTSG)

12. WILMS’ TUMOUR- Staging
Staging
system
utilized by the
Society of
Paediatric
Oncology
(SIOP)

13. WILMS’ TUMOUR- Differential Diagnosis
Mainly has to differentiate from
Neuroblastoma

14. WILMS’ TUMOUR- Treatment
 The treatment for children with stage I
or II Wilms’ tumor and favorable
histology is nephrectomy followed by
18 weeks of combination chemotherapy
with vincristine and dactinomycin.
 The treatment for children with stage III
Wilms’ tumor and favorable histology is
nephrectomy followed by tumor-bed or
whole-abdomen irradiation and 21 weeks of
combination chemotherapy with
vincristine, dactinomycin, and doxorubicin.
 The treatment for children with stage IV
Wilms’ tumor and favorable histology is
nephrectomy followed by whole-lung
irradiation and 21 weeks of combination
chemotherapy with vincristine,
dactinomycin, and doxorubicin.

15. WILMS’ TUMOUR

16. Peripheral Arterial Diseases(PAD)