[Idiopathic retroperitoneal fibrosis misdiagnosed as renal cancer: a case report and literature review].

A 51-year-old male patient was presented to our hospital for inspection of right renal space-occupying lesions. CT revealed soft tissue density in the right renal pelvis and renal pelvis ureter transitional crumb, for which a clinical diagnosis of right renal cancer was made. After laparoscopic radical resection of the right kidney, pathological examination supported the diagnosis of idiopathic retroperitoneal fibrosis. With an unclear pathogenesis, idiopathic retroperitoneal fibrosis presents with atypical clinical manifestations but shows specific features in imaging examination. Its treatment is individualized according to the specific condition for which conservative medical or surgical treatment can be considered. Retroperitoneal fibrosis has a low incidence and a high misdiagnosis rate, and imaging examinations remain currently the primary modality for diagnosis with specific findings.