Wilms tumor or Wilms tumor, also known as nephroblastoma, is a cancer of the kidneys that typically occurs in children, rarely in adults. ; and occurs most commonly as a renal tumor in child patients. It is named after Max Wilms, the German surgeon (1867–1918) who first described it.Approximately 650 cases are diagnosed in the U.S. annually. The majority of cases occur in children with no associated genetic syndromes; however, a minority of children with Wilms tumor have a congenital abnormality. It is highly responsive to treatment, with about 90 percent of children being cured. Signs and symptoms
Typical signs and symptoms of Wilms tumor include the following:
a painless, palpable abdominal mass
loss of appetite
abdominal pain
fever
nausea and vomiting
blood in the urine (in about 20% of cases)
high blood pressure in some cases (especially if synchronous or metachronous bilateral kidney involvement)
Rarely as varicocele

Pathogenesis
Wilms tumor has many causes, which can broadly be categorized as syndromic and non-syndromic. Syndromic causes of Wilms tumor occur as a result of alterations to genes such as the Wilms Tumor 1 (WT1) or Wilms Tumor 2 (WT2) genes, and the tumor presents with a group of other signs and symptoms. Non-syndromic Wilms tumor is not associated with other symptoms or pathologies. Many, but not all, cases of Wilms tumor develop from nephrogenic rests, which are fragments of tissue in or around the kidney that develop before birth and become cancerous after birth.
Extensive tumor involvement of renal sinus soft tissue.In Stage III (20% of cases), 1 or more of the following criteria must be met:
Inoperable primary tumor. Lymph node metastasis. Tumor is present at surgical margins. Tumor spillage involving peritoneal surfaces either before or during surgery, or transected tumor thrombus. The tumor has been biopsied prior to removal or there is local spillage of tumor during surgery, confined to the flank.Stage IV (10% of cases) Wilms tumor is defined by the presence of hematogenous metastases (lung, liver, bone, or brain), or lymph node metastases outside the abdominopelvic region.Stage V (5% of cases) Wilms tumor is defined by bilateral renal involvement at the time of initial diagnosis. For patients with bilateral involvement, an attempt should be made to stage each side according to the above criteria (stage I to III) on the basis of extent of disease prior to biopsy. Treatment and prognosis
The overall 5-year survival is estimated to be approximately 90%, but for individuals the prognosis is highly dependent on individual staging and treatment. Early removal tends to promote positive outcomes. Tumor-specific loss-of-heterozygosity (LOH) for chromosomes 1p and 16q identifies a subset of Wilms tumor patients who have a significantly increased risk of relapse and death. LOH for these chromosomal regions can now be used as an independent prognostic factor together with disease stage to target intensity of treatment to risk of treatment failure.