Renal lymphoma: MR appearance with diffusion-weighted imaging.

Imaging of renal lymphoma on magnetic resonance imaging and diffusion-weighted imaging is not well documented in the literature. We present a case of renal lymphoma in a 61-year-old patient with computed tomography and magnetic resonance imaging correlation. The lymphomatous lesions demonstrate mild enhancement and restricted diffusion. Differential considerations for hypoenhancing masses include papillary or chromophobe renal cell carcinoma, lymphoma, urothelial tumor, or metastasis, all of which have different management pathways. Apparent diffusion coefficient values can be obtained using diffusion-weighted imaging, and may be useful in identifying focal renal lesions, especially on noncontrast imaging. Apparent diffusion coefficient values may be helpful in differentiating between some of these lesions, although more investigation is needed.