Figure 7e. Surgical hyperattenuating mass in a 63-year-old asymptomatic man. (a-c) Unenhanced (a), nephrographic phase (b), and excretory phase (c) CT scans show a well-defined, homogeneous, 3-cm-diameter lesion. The region of interest for measurement was in the center of the mass. The mass enhances 13 HU on the nephrographic phase image (b), then de-enhances 7 HU on the excretory phase image (c). If nephrographic phase images had not been obtained, the apparent enhancement would have been 6 HU. (d) Longitudinal sonogram shows that the lesion (arrows) is solid. (e) Gross photograph of the excised mass shows a well-defined 3-cm-diameter mass, which was a papillary renal cell carcinoma.