Analysis of Cases of CT Misdiagnosis of Xanthogranulomatous Pyelonephritis

Abstract

Objective To analyze the CT manifestations of xanthogranulomatous pyelonephritis (XGPN)and the causes of misdiagnosis and to further understand radiological diagnosis of XGPN.Methods The CT and clinical manifestations of 7 cases of XGPN were analyzed retrospectively.And the density,enhancement and morphologic characters of the lesions,calculus,calcification and perirenal spaces were observed.All the cases were pathologically proved.Results All the 7 cases were underwent enhancement scanning.6 cases of the 7 located in left kidney,while 1 case of 7 in the right.The diffusive XGPN shows cystic—solid multi—occupying with the whole kidney involved and kidney,renal pelvis and calices enlarged.The lesions were extensive with unclear border which made the perirenal space dim,renal fasciae thicken and with the abscess formation of psoas and abdominal wall.The localized XGPN shows mass in the renal parenchyma with low density,clear border after enhancement and rim enhancement.The lesions with slightly low density were relatively significant enhancement but lower than the renal parenchyma.Diseases were preoperatively misdiagnosed as 3 cases of renal abscess,2 cases of renal cell carcinoma,one case of renal tuberculosis,and one case of renal calculi complicated with hydronephrosis.Conclusion As there is no significant diagnostic sign of XCPN,misdiagnosis is easily found before operation.Anyhow,CT plain scan plus enhanced scan is generally accepted as the best method now. Key words: Xanthogranulomatous pyelonephritis(XGPN); Tomography X-ray computed