Wilms Tumor

Findings: There is a large heterogeneous partially enhancing mass arising from the left kidney. There is no renal vein involement. The mass is displacing adjacent retroperitoneal structures, like the pancreas, in an anterior direction.

Additional imaging and pathologic correlation proved this to be a stage 1 Wilm's tumor.

Discussion: Wilms tumors are malignant tumors of the primitive metanephric blastema. It is the commonest renal mass in children aging 1-8 years old.

The differential diagnostic considerations include:

- multilocular cystic nephroma
- neuroblastoma
- clear cell sarcoma of the kidney
- rhabdoid tumor of the kidney
- renal cell carcinoma
- congenital mesoblastic nephroma: hamartomatous renal tumor, generally benign (fetus to newborn)

The staging system for Wilms tumor is:
Stage I: confined to kidney, completely excised
Stage II: local extension, completely resected
Stage III: incomplete resection, no distant metastases
Stage IV: distant metastases
Stage V: bilateral synchronous tumors

Source: StatDx.com