Isolated extrarenal papillary carcinoma in a child.

A previously healthy 12-year-old boy presented with a mass in the right retroperitoneum adjacent to an ipsilateral hypoplastic kidney. Complete resection of the tumor and kidney were done. The tumor was found to be papillary adenocarcinoma lying 3 cm apart from a contracted kidney, which was free of tumor. No adjuvant therapy was given. After 50 months of follow-up the child is healthy without evidence of tumor recurrence.