View larger version (157K)

Figure 19b.   High-grade large cell lymphoma in a 35-year-old man. (a) Contrast-enhanced CT scan demonstrates patchy tumor infiltration within the kidneys. The kidneys have retained their normal contour, a finding that is characteristic of infiltrative lymphoma. (b) On an unenhanced CT scan, the infiltration is undetectable, which underscores the importance of contrast-enhanced CT for diagnosis.