Pediatric renal cell carcinoma as second malignancy: reports of two cases and a review of the literature.

Pediatric renal cell carcinoma (RCC) is relatively rare and appears to comprise a group of tumors distinct from RCCs typically seen in adults. Recently described tumors show an association with neuroblastoma or specific chromosomal translocations. Only rarely have other childhood cancers been associated with pediatric RCC. We present two cases of pediatric RCC following treatment of other childhood malignancies not previously described, supratentorial primitive neuroectodermal tumor and acute lymphoblastic leukemia, and review the literature on pediatric RCC. As the RCCs were discovered as incidental radiologic findings, we emphasize the importance of close follow-up (including imaging) at routine intervals in survivors of childhood malignancies, not only to monitor for recurrence or metastasis, but also for development of a second malignancy.