Objective  To investigate the diagnosis and differential diagnosis of renal and retroperitoneal tumors in children with CT.   Methods  CT findings in 189 cases of pathologically confirmed renal and retroperitoneal tumors

including nephroblastoma in 71 cases

neurogenic tumor in 89 cases (neuroblastoma in 70 cases

ganglioneuroblastoma in 2 cases and ganglioneuroma in 17 cases)

teratoma in 18 cases and lymphoma in 11 cases

were retrospectively analyzed.   Results  CT showed that nephroblastoma was a round or oval encapsuled mass usually resulting in renal destruction

the residual kidney was a crescent-shaped encapsuled mass which is easy to lead to thrombosis of renal vein and inferior vena cava due to tumor. The manifestations of neuroblastoma were similar to those of ganglioneuroblastoma

usually with calcification and embed vessels

and could invade the kidneys and often metastasize to lymph nodes

cranium and brain

bones and liver. The ganglioneuroma was manifested as a small oval-shaped low dense mass in adrenal gland area or in paravertebral

with no exacerbation or slight exacerbation in its early stage. Lymphoma was located around the median line and presented as an irregular mass fused by multiple lymph nodes embedding the vessels loosely. Teratoma

usually occurred on one side of the retroperitonium

was characterized by calcification/ossification and fat tissue.   Conclusion  CT is of a higher value for the diagnosis and differential diagnosis of renal and retroperitoneal tumors in children.