What is the classical differential diagnosis for a large mass in this location in a young child?
What features are helpful in this case in strongly favouring a Wilms tumour?
Mass arises from the kidney. Child is 3 years old. Calcifications are absent. Mass remains relatively well circumscribed, without infiltration or insinuation around adjacent structures.
CT of the abdomen with oral and intravenous contrast demonstrates a very large heterogeneous mass arising from the right kidney, and displacing the remaining renal parenchyma anteromedially. The mass contains mixed solid and cystic areas only only marginally enhances.
On these images there is no convincing evidence of spread into adjacent structures. There is no convincing involvement of the renal vein or IVC. No convincing nodal or distant metastatic disease in the portions imaged.