title: Retroperitoneal malignant peripheral nerve sheath tumor replacing an absent kidney in a child.
abstract: Malignant peripheral nerve sheath tumors (MPNSTs) are nonrhabdomyosarcoma soft tissue sarcomas with rare occurrence in children specially in the retroperitoneum. We describe a young child who presented with an abdominal mass. Both ultrasound and computed tomography revealed a large right-sided abdominal mass in the anatomic place of right kidney, while no kidney or ureter was observed at that side. He underwent surgical resection of the tumor with a primary impression of Wilms tumor. To the authors' knowledge, this is the first case of retroperitoneal malignant peripheral nerve sheath tumor and absent kidney. This case suggests the very rare probability of association of MPNSTs in children with genitourinary tract anomalies such as renal agenesis.
authors.affiliation: Pediatric Congenital Hematologic Disorders Research Center, Shahid Beheshti University of Medical Sciences, Tehran 15468-15514, Iran ; Mofid Children's Hospital, Dr. Shariati Avenue, Tehran, Iran.
authors.forename: Samin
authors.initials: S
authors.lastname: Alavi
authors.affiliation: Pediatric Congenital Hematologic Disorders Research Center, Shahid Beheshti University of Medical Sciences, Tehran 15468-15514, Iran.
authors.forename: M T
authors.initials: MT
authors.lastname: Arzanian
authors.affiliation: Pediatric Pathology Research Center, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran 15468-15514, Iran.
authors.forename: Yalda
authors.initials: Y
authors.lastname: Nilipour