THE PROBLEM of the roentgen diagnosis of retroperitoneal tumors in infants and children is simplified by the fact that these tumors are almost exclusively one of three types: (1) renal embryoma (Wilms tumor), (2) neuroblastoma, and (3) unattached embryoma (teratoma). Other retroperitoneal tumors, such as rhabdomyosarcoma and lymphoma, occur in children rarely, but the numerous other tumor types commonly encountered in adults are virtually unknown in these young patients. Thus when an infant or child with evidence of abdominal mass is presented for roentgenologic study, the various diagnostic procedures should be carried out with the purpose of demonstrating the features of one of these three retroperitoneal tumors.
The nature of these tumors can be briefly summarized.
Renal Embryoma (Wilms Tumor).
—This is the usual renal tumor of early life. It comprises 20% of neoplasms in children. Although first described by Gairdner in 1828, Wilms's classic description has linked his