Wilms Tumor

  • Etiology: renal origin, 30% of unilateral and 100% of bilateral Wilms tumor are due to nephrogenic rests
  • Imaging: claw sign, deforms the collecting system showing it is an intrarenal mass, pushing tumor that displaces vessels, 10% are calcified
  • Complications: renal vein / inferior vena cava tumor thrombus, involves contralateral kidney either synchronous or metachronous in 10%, metastasis to lung, bone, liver
  • Clinical: associated with Beckwith-Wiedemann syndrome

Cases of Wilms Tumor

MRI of Wilms tumor
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.
CXR of lung metastasis in Wilms tumor
CXR PA shows a large round opacity just lateral to the left pulmonary artery which is located anteriorly on the lateral view.
Gross pathological image of Wilms tumor
Gross pathological image shows a whitish-tan mass with areas of hemorrhage and necrosis arising from the lower pole of the kidney. Note the compression of the adjacent renal tissue which manifests itself on imaging as the renal “claw” sign.