MRI manifestations of renal oncocytoma

Objective: To analyze the MRI findings of renal oncocytoma, and to improve the ability for the diagnosis. Methods: We retrospectively review MRI findings of 6 cases of renal oncocytoma which proved by pathology. Results: Six cases had solitary lesion in each, and 1 of them accompanied with renal clear-cell carcinoma. Tumors appeared as round with diameter 1.5 to 3.8 cm, and well-defined margin. On T1WI, 3 tumors showed hypo-intensity, and 3 had iso-intensity. On T2WI, 3 tumors were iso- to hypo-intensity mixed with slightly hyperintensity, 1 tumor was iso- to hypo-intensity with center star-like high signal, and Low signal was detected in 2 tumors. Dynamic scan demonstrated that homogenous enhancement in the 3 tumors, heterogenous enhancement in 1 tumor, with parenchyma part of tumors with homogenous enhancement, and center scar delayed enhancement. Another 2 tumors were showed as spoke-like enhancement. Conclusion: MR could demonstrate renal oncocytoma and it could be helpful to the diagnosis. (authors)