We describe a 4-year-old female patient with a persistent paraspinal mass following chemotherapy for Wilms tumor. A discordant response to chemotherapy prompted biopsy of the persistent mass, which revealed a ganglioneuroma. This report highlights the synchronous occurrence of different tumors in the same patient, and suggests that repeat biopsies should be considered when contiguous tumor masses do not respond as expected.
2010 Wiley-Liss, Inc.