Collision tumors in children: A review of the literature and presentation of a rare case of mesoblastic nephroma and neuroblastoma in an infant

A mass made up of 2 distinct synchronous primary malignant tumors is a rare event in adults, and exceedingly so in children. Such lesions have been called collision tumors. Reported here is an infant who was found to have a collision tumor comprised of a neuroblastoma and a congenital mesoblastic nephroma, in contiguity, in the right kidney. This is the first report of a collision tumor in an infant. This also is the first report of a synchronous occurrence of a neuroblastoma and a congenital mesoblastic nephroma. The authors present this case and discuss the available literature. Copyright (C) 2000 by W.B. Saunders Company.