nephroblastoma

Preschooler
with Wilms tumor. CXR PA shows a large round opacity just lateral to the left pulmonary artery which is located anteriorly on the lateral view.The diagnosis was a lung metastasis in a patient with Wilms tumor.
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Infant with
an abdominal mass. Axial CT without intravenous contrast but with oral contrast of the abdomen (above) shows a large right sided abdominal mass that is calcified. Axial CT with intravenous and oral contrast of the abdomen (below) shows the mass is heterogenous in appearance, does not cross the midline, and the normally enhancing right kidney is demonstrating a claw sign along its posterior aspect.The diagnosis was Wilms tumor of the right kidney.
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Preschooler
with an abdominal mass. Axial CT with contrast of the abdomen (above) shows a large non-calcified and non-enhancing mass crossing the midline with multiple retrocrural lymph nodes present. Axial CT (below) shows the mass is arising from the upper pole of the right kidney. The right renal vein and inferior vena cava are not clearly seen.The diagnosis was Wilms tumor of the right kidney with probable tumor invasion of the right renal vein and inferior vena cava.
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School ager
with a right abdominal mass. Axial CT without contrast of the abdomen (above) show a large right renal mass with some coarse calcifications within it. Axial CT with contrast (middle and below) shows a low density mass to be arising from the hilum of the right kidney and to be approaching the midline. The inferior vena cava appears to be clear of tumor as does the left kidney.The diagnosis was Wilms tumor.
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Toddler with
a right-sided abdominal mass. AXR (above left) shows displacement of the bowel out of the right side of the abdomen. Sagittal US of the right kidney (above right) shows a large right renal mass that spares the upper pole of the right kidney. Coronal T1 MRI with contrast of the abdomen (below left) shows a large mass that is heterogenous in appearance that arises from the lower pole of the right kidney and that is demonstrating a claw sign superiorly. Axial T2 MRI (below right) again shows the heterogenous nature of the mass due to hemorrhage and necrosis.The diagnosis was Wilms tumor.
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Toddler with
a left abdominal mass. The diagnosis was Wilms tumor of the left kidney and nephrogenic rests from nephroblastomatosis in the right kidney.The diagnosis was Wilms tumor of the left kidney and nephrogenic rests from nephroblastomatosis in the right kidney.
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Wilms tumoru
with bony-mandibular, rib and calvarial metastases. A large heterogeneously enhancing mass seen in upper pole and interpolar region of right kidney. A lytic lesion in the right second rib with adjacent large soft tissue is also seen.
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Wilms tumoru
with bony-mandibular, rib and calvarial metastases. The mass arising from the right kidney with a rim of compressed residual renal parenchyma (claw sign). A lytic lesion is also noted in the right second rib with a large soft tissue.
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Synchronous
choroid plexus papilloma and Wilms tumor in a girl, disclosing a Li-Fraumeni syndrome. Radiological studies. Panel a Intravenous contrast-enhanced abdominal CT, coronal view: a solid, heterogeneous tumor in the upper pole of the left kidney is identified (upper, thin arrow), with an adjacent subcapsular perirenal hematoma (lower, thick arrow). The actual diameters were 36 mm × 28 mm × 27 mm in anteroposterior, transverse, and craniocaudal planes. Panel b Cerebral MRI, T2-weighted sequence, axial view. A solid supratentorial intraventricular tumor with left parietal lobe extension is shown. Cystic areas in the basal peripheral and medial aspects are identified .The tumor causes localized ventriculomegaly, vasogenic edema and midline shift. The actual diameters (tumor and cysts) were 81 × 59 × 75 mm in the anteroposterior, transverse, and craniocaudal planes. Panel c Non-enhanced Brain CT scan after shunt insertion. Axial reconstruction. A left parietal tumor with extensive calcification is shown. Ventricular catheter tip is in the right frontal ventricular horn
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Toddler with
presumed urinary tract infection. Sagittal US of the left kidney (upper left) shows a round hyperechoic lesion in the lower pole of the kidney. Axial T2 MRI without contrast of the abdomen (upper right) and coronal T1 MRI without (lower left) and with (lower right) contrast of the abdomen shows a well-circumscribed, solid T1 hypointense and T2 isointense mass in the lower pole of the left kidney that enhances minimally.The diagnosis was Wilms tumor of the left kidney.
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Teenager with
past history of Wilms tumor. CXR AP (above) shows a soft tissue density projecting in the right cardiophrenic angle. Axial CT with contrast of the chest (below) shows a soft tissue mass in the right posterior costophrenic sulcus.The diagnosis was lung metastasis in a patient with Wilms tumor.
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Preschooler
with gross hematuria. Axial (left) and coronal (right) CT with contrast of the abdomen shows a large rounded solid heterogenous mass arising from the upper pole of the right kidney and a large rounded solid heterogenous mass arising from the center of the left kidney.The diagnosis was bilateral Wilms tumor.
pediatricimaging.org • CC-by-nc-sa 4.0
Preschooler
with abdominal pain. Axial (left) CT with contrast of the abdomen shows a large cystic mass with septations in the left side of the abdomen. Coronal immediate image (above right) shows a claw sign proving the left kidney is the organ of origin of the mass. Coronal delayed image (below right) shows the mass has a mural nodule superiorly within it.The diagnosis was cystic Wilms tumor.
pediatricimaging.org • CC-by-nc-sa 4.0
Toddler with
abdominal pain and distension, hematuria and lethargy for 2 months. Axial (above right), coronal (below middle) and sagittal (below right) CT with contrast of the abdomen shows a large heterogenous non-calcified mass that fills the entire left side of the abdomen. The inferior vena cava (to the right of the aorta) was distended with tumor thrombus. Multiple liver (above left) and lung (below left) lesions are also seen.The diagnosis was Wilms tumor with liver metastases and lung metastases and invasion of the inferior vena cava.
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Preschooler
with a right sided abdominal mass. Axial CT with contrast of the abdomen shows a large oval low density lesion arising from the right kidney and causing a claw sign. There is also a second smaller round low density lesion arising from the posterior aspect of the left kidney.The diagnosis was bilateral Wilms tumor.
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Radiopaedia • CC-by-nc-sa 3.0 • de

Wilms tumor, also known as nephroblastoma, is a malignant pediatric renal tumor.

Epidemiology

Wilms tumors are the most common pediatric renal mass, accounting for over 85% of cases and accounts for 7% of all childhood cancers . It typically occurs in early childhood (1-11 years) with peak incidence between 3 and 4 years of age. Approximately 80% of these tumors are found before the age of 5 years. When part of a syndrome (see below) they occur even earlier, typically between 2 and 24 months of age .

There is no recognized gender predilection, however, presentation is a little later in females . The vast majority are unilateral with less than 5 % occurring bilaterally.

Clinical presentation

Clinical presentation is typically with a painless upper quadrant abdominal mass. Hematuria is seen in ~20% of cases and pain is uncommon. On examination hypertension due to excessive renin production is found in up to 25% of patients and acquired von Willebrand disease is seen in 8% .

Associations

Although most cases are sporadic and only 2% of cases are familial, a number of associations are recognized :

Risk factors

Pathology

The tumor typically arises from mesodermal precursors of the renal parenchyma (metanephros). Increasingly gene loci are being implicated on chromosome 11 (WT1: 11p13 and WT2: 11p15) as well as WTX on chromosome X, B-catenin on chromosome 3 or TP53 on chromosome 17 .

On gross inspection, these tumors are usually well-circumscribed or macrolobulated. Hemorrhage and central necrosis are common findings .

Radiographic features

Wilms tumors are usually large heterogeneous solid masses which displace adjacent structures. Occasionally they may be mostly cystic.

Metastases are most commonly to lung (85%), liver and local lymph nodes . Similar to renal cell carcinoma tumor thrombus into the renal vein, IVC and right atrium is also characteristic of advanced disease. See also: Wilms tumor staging.

Plain radiograph

Abdominal x-ray typically reveals a large soft tissue opacity displacing bowel. This is only relevant if found incidentally since a radiograph should never be used for the assessment of an abdominal mass. The only exception would be a resource-poor setting where an abdominal radiograph is the only imaging modality available.

Ultrasound

Ultrasound is a very useful examination and in almost every situation will be the primary investigation of choice. It is helpful to localize the mass to the kidney and also distinguish from other causes of renal masses (e.g. hydronephrosis). Although many of the features seen on CT/MRI can also be identified on US, the former are required to adequately stage the disease and is established in protocols for Wilms tumor staging in North America and Europe .

Doppler examination can be performed to examine the renal vein and IVC to assess for the presence of tumor thrombus.

CT

Wilms tumors are heterogeneous soft-tissue density masses with infrequent areas of calcification (~15%)  and fat-density regions. Enhancement is also patchy and allows for better delineation of the relationship between the mass and kidney. 10-20% of cases have lung metastases at the time of diagnosis .

MRI

Where MRI is available it is the investigation of choice for staging since it does not involve ionizing radiation. It is also the most accurate modality in assessing for IVC involvement where protocols have been optimized. These tumors appear heterogeneous on all sequences and frequently contain blood products.

  • T1: hypointense
  • T1 C+ (Gd): heterogeneous enhancement
  • T2: hyperintense
Nuclear medicine

Bone scans are not routine as the tumor metastasizes to bones very late. F-18 FDG PET/CT is increasingly used as a problem-solving tool and to distinguish scar tissue from residual active tumor.

Treatment and prognosis

Unilateral Wilms tumors are, usually, treated by a combination of nephrectomy and chemotherapy. Occasionally chemotherapy can be administered prior to surgery to downstage the tumor . This is especially useful when tumors are bilateral.

Radiotherapy has a limited role, but may be employed in cases of peritoneal spread or incomplete resection .

Cure is now possible in ~90% of cases. Recurrence is seen both within the tumor bed, as well as distally within the lungs or liver .

History and etymology

This entity was popularized by Max Wilms in 1899, although prior descriptions had been published by Osler in 1880 and Birch-Hirschfeld in 1898 .

  • Max Wilms (1867-1918), surgeon; Heidelberg, Germany
  • Felix Victor Birch-Hirschfeld (1842-1899), physician; Leipzig, Germany
  • William Osler (1849-1919), physician; Montreal, Canada

Differential diagnosis

General imaging differential considerations include:

See also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Nephroblastom:
Angiomyolipom
 
Wikipedia • CC BY-SA 3.0
Neuroblastom
 
Wikipedia • CC BY-SA 3.0
Nierenzellkarzinom
 
Wikipedia • CC BY-SA 3.0
Nephroblastomatose
 
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Nierenabszess
 
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pädiatrische
Nierentumoren
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Wilms-Tumor
Metastasen
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