MRI features of renal oncocytoma / 中华放射学杂志

ABSTRACT

Objective To investigate the MRI features of renal oncocytoma(RO). Methods We retrospectively analyzed the data of 26 patients by histologically confirmed with RO in Chinese PLA General Hospital from September 2006 to May 2017 and performed pre-operative MRI and dynamic contrast-enhanced MRI.Lesions were divided into two groups based on the diameterlarge group with large than 3 cm(16 cases,16 lesions)and small group with less than 3 cm(10 cases,11 lesions).Features of each lesion were analyzed, including location, pseudocapsules, lipids and other 11 indicators. Tumor imaging features were compared between two groups by univariate and multivariate logistic regression analysis. Results Of 27 RO lesions, 12 were located in the left kidney and 15 in the right kidney. Twenty five lesions appeared exophytic(92.6%,25/27),10 lesions showed exophytic angular interface(37.0%,10/27), 25 lesions showed pseudocapsule(92.6%,25/27),4 lesions appeared lipid(14.8%,4/27),2 lesions showed cystic degeneration or necrosis(7.4%,2/27),1 lesion showed hemorrhage(3.7%,1/27),13 lesions appeared fibrous scar(48.1%,13/27),19 lesions with moderate or intense enhancement in the corticomedullary phase (70.4%, 19/27), 9 lesions with wheel-spoke-like enhancement (33.3%, 9/27), and 2 lesions showed segmental enhancement inversion (7.4%, 2/27). Univariate logistic regression exhibited statistically significant correlation between exophytic angular interface with renal parenchyma,fibrous scar,moderate or intense enhancement in the corticomedullary phase,and wheel-spoke-like enhancement of the tumors both in small and large RO groups with OR value of 0.054, 9.898, 8.400 and 10.000, respectively. In the multivariate logistic regression analysis, exophytic angular interface with renal parenchyma and intense enhancement in the corticomedullary phase were found to be high risk factors with OR value of 0.033 and 15.381,respectively.Conclusions The main manifestation of RO on MRI is that both kidneys can occur, with many exogenesis, pseudocapsules, but less lipids, cystic degeneration, necrosis, hemorrhage and segmental enhanced reversal;smaller lesions(diameter<3 cm)tend to conical interface,while larger lesions (diameter≥3 cm)may have fibrous scars,spoke-shaped enhancement,moderate and significantly enhanced cortical phase characteristics.