We present the case of a 50-year-old man with a solitary mass lesion in the right kidney. Characteristics on ultrasound were a thick irregular hypoechoic wall and a slightly hyperechoic center. Computed tomography depicted the lesion as spontaneously hyperdense at its base. After administration of intravenous iodinated contrast only partial enhancement in the peripheral wall was seen. On MR imaging the lesion was hypointense on T1-weighted images, and T2-weighted images demonstrated a thick irregular hypointense peripheral wall and an intralesional fluid debris level. Gadolinium-chelates were not administered.