2. • Wilms' tumor or nephroblastoma is
malignant tumor of the kidneys that
typically occurs in children. Dr. Max Wilms
, the German surgeon (1867–1918) first
described this kind of tumor.
• Wilms tumor is the fifth most common
pediatric malignancy (7% of all childhood
tumors).
3. • Incidence is 1 in 10,000, girls are slightly
more affected
• 70% of cases occur before the child is 5
years of age.
• Most commonly unilateral, but in 5% -
10% both kidneys are involved.
4. • Approx 500 cases are diagnosed in the U.S.
annually.
• The majority (75%) occurs in otherwise normal
children; a minority (25%) is associated with
other developmental abnormalities.
• It is highly responsive to treatment, with about
90% of patients surviving at least five years.
6. It is believe that tumor begins to grow as a
fetus develops in the womb, with some cells
that are destined to form into the kidneys
malfunctioning and forming a tumor.
The exact etiology of the tumor are still being
investigated.
7. • Tumor is exceedingly vascular, soft,
mushy, or gelatinous in character.
• Wilms tumor has capacity for rapid growth,
usually grows to a large size.
8. • Tumor is usually uniform, well demarcated by a
pseudocapsule of compressed renal tissue.
• Tumor develops from primitive renal tissue and
can have epithelial ( tubules and glomeruli),
stromal (fat, skeletal muscles, cartilage) and
blastemal elements (An immature material from
which cells and tissues develop).
9. Wilms tumor may be associated with
• Hemihypertrophy-one side of body is
larger than other
• Aniridia (complete loss of iris) and
• Genitourinary anomalies.
10. Pathophysiology
• WT1 gene; dominant oncogene (at chromosome
11p13), WT2 gene (at chromosome 11p15)
(a tissue-specific gene for renal blastemal cells
and glomerular epithelium)
• Leads to abnormal proliferation of the
metanephric blastemal cells (primitive
embryologic cells of the kidney).
• promote changes that may lead to the formation
of Wilms tumor.
11. Clinical manifestations
• Wilms tumor is diagnosed at a mean age
of 3.5 years.
• The most common feature is an upper
quadrant abdominal mass (firm,
nontender)
12. • Abdominal pain occurs in 30%-40% of
cases, related to rapid growth of tumor.
• Urethral obstruction due to compression
• Constipation, vomiting, abdominal ditress,
anorexia, weight loss and dyspnea due to
enlargement of tumor.
13. • Other signs and symptoms of Wilms tumor
include hypertension, fever caused by
tumor necrosis, hematuria, and anemia.
14. • The neoplasm metastasize either by direct
extension or by bloodstream. They may
invade perirenal tissues, lymph nodes, the
liver, the diaphragm, abdominal muscles
and the lungs.
• Invasion of bone and brain are less
common.
15. Diagnostic evaluation
Laboratory studies:
• CBC with differential for baseline data
• Platelet count:Coagulation abnormalities
• Urinalysis for hematuria and urine culture
• Liver function tests
• Renal function tests
• Blood chemistry; sr. electrolytes, uric acid
16. Imaging Studies
• Ultrasonography
– Initial diagnosis of a renal or abdominal mass,
– Possible renal vein or inferior vena cava (IVC)
thrombus (Doppler flow study may be helpful
in the setting of vascular invasion.)
– Information regarding liver and other kidney
17. • CT scanning of the chest and abdomen
– Differential diagnosis of a kidney tumor versus
adrenal tumor (neuroblastoma)
– Liver metastases
– Status of opposite kidney
– Lymph node assessment
– Status of chest with respect to metastases
18. • IVP
• Chest radiography - As a baseline for
pulmonary metastases
• Bone scan
• Magnetic resonance imaging
19. Histologic Findings
• Favorable histology (90% of cases) is
characterized by all 3 histological
elements, without any anaplastic features.
The cure rate in these cases is close to
90%.
20. • Unfavorable histology (10% of cases) is
characterized by the presence of
anaplasia.
• Anaplasia is defined as nuclear
enlargement, and abnormal mitoses.
21. If tumor reveals sarcoma type of tumor then
• Bone scan
• Bone marrow aspirate
• Biopsy
22. Staging and treatment
• Staging is determined by combination of
imaging studies and pathology findings.
• Treatment strategy is determined by the
stage.
23. Stage I (43% of patients)
• For stage I Wilms' tumor, 1 or more of the following
criteria must be met:
• Tumor is limited to the kidney and is completely excised.
• The surface of the renal capsule is intact.
• The tumor is not ruptured or biopsied (open or needle)
prior to removal.
• No involvement of extrarenal or renal sinus lymph-
vascular spaces
• No residual tumor apparent beyond the margins of
excision.
• Metastasis of tumor to lymph nodes not identified.
24. Treatment:
• Nephrectomy +/- 18 weeks of
chemotherapy depending on age of
patient and weight of tumor. EG: less than
2 years old and less than 550g only
requires Nephrectomy with observation.
• Outcome: 98% 4-year survival; 85% 4-
year survival if anaplastic
25. Stage II (23% of patients)
For Stage II Wilms' tumor, 1 or more of the following criteria
must be met:
• Tumor extends beyond the kidney but is completely
excised.
• No residual tumor apparent at or beyond the margins of
excision.
• Any of the following conditions may also exist:
– Tumor involvement of the blood vessels of the renal and/or
outside the renal parenchyma.
– The tumor has been biopsied prior to removal or there is local
spillage of tumor during surgery, confined to the flank.
– Extensive tumor involvement of renal soft tissue.
26. Treatment:
• Nephrectomy + abdominal radiation + 24
weeks of chemotherapy
• Outcome: 96% 4-year survival; 70% 4-
year survival if anaplastic
27. Stage III (23% of patients)
For Stage III Wilms' tumor, 1 or more of the
following criteria must be met:
• Unresectable primary tumor.
• Lymph node metastasis.
• Tumor is present at surgical margins.
• Tumor spillage involving peritoneal
surfaces either before or during surgery.
28. Treatment:
• Abdominal radiation + 24 weeks of
chemotherapy + nephrectomy after tumor
shrinkage
• Outcome: 95% 4-year survival; 56% 4-
year survival if anaplastic
29. Stage IV (10% of patients)
• Stage IV Wilms' tumor is defined as the
presence of hematogenous metastases
(lung, liver, bone, or brain), or lymph node
metastases outside the abdomenopelvic
region.
30. Treatment:
• Nephrectomy + abdominal radiation + 24
weeks of chemotherapy + radiation of
metastatic site as appropriate.
• Outcome: 90% 4-year survival; 17% 4-
year survival if anaplastic
31. Stage V (5% of patients)
• Stage V Wilms’ tumor is defined as bilateral
renal involvement at the time of initial diagnosis.
• The 4-year survival in 94% patients with stage I
or stage II; 76% for with stage III.
• Treatment: Individualized therapy based on
tumor burden
34. • Stage I actinomycin and vincristine for 11-
15 weeks
• Stage II actinomycin and vincristine for 15
months
• Stage III actinonycin, vincristine and
adriamycin for 15 months,
35. • Stage IV actinomycin, vincristine, and
adriamycin for 15 months. If response is
slow then cyclophosphamide is added
36. • Stage V (bilateral wilms tumor)
1. Excision of tumor
2. If not possible, confirmatory biopsies
then treated with vincristine and
actinomycin D for 3-6 months. If no
satisfactory resolution seen after 3
months, radiation is added to both
kidneys
37. • A second look surgery is planned after 6
months of therapy, if not possible
chemotherapy may be tried for an
additional 9 months
38. • In totally inoperable cases with no
metastatic disease bilateral nephrectomy
and renal transplantation may be only
viable operation.