CT and MRI manifestations of adult renal adenoma

PAN Dongmei; LIU Hongmei; LI Zhengteng; WANG Zuoxiang; WANG Min; YU Yongmei; DAI Chenchen

Abstract：Objective To investigate the CT and MRI findings of metanephric adenoma so as to improve the diagnostic accu-racy.Methods The CT and MR findings of 13 cases of MA with pathologically-confirmed were analyzed.Results The 13 pa-tients included 2 males and 11 females.10 cases occurred in the renal cortex and 3 cases in the corticomedullary region.Seven le-sions were solid.Six lesions were cystic solid and septum was seen in 3 cases.Calcification was found in 4 cases.Ten cases under-went CT scan.Plain scan of solid part showed equal or slightly high density.Eight cases underwent MRI scan,two lesions showed complete pseudocapsules on T2WI and 4 incomplete pseudocapsule.DWI showed high signal,ADC value decreased.T1WI showed equal or slightly lower signal intensity,hemorrhage was seen in 3 cases.T2WI showed equal-lower or slightly higher sig-nal on MRI.The lesions showed mild to moderate progressive enhancement on enhanced scan,of which 2 cases showed centrip-etal filling enhancement.The enhancement degree was lower than that of normal renal parenchyma.One case was accompanied by retroperitoneal lymph node metastasis.Conclusion It is highly suspected of the possibility of metanephric adenoma when we see a solid or cystic solid renal mass with exogenous growth,accompanied by calcification,showing mild to moderate progres-sive enhancement in middle-aged women.The cystic solid lesions may have internal partitions.The combination of CT and MR can improve the diagnostic accuracy of the disease.