Papillary renal cell carcinoma in a young adult: serial changes in diagnostic images.

In renal tumors, we often encounter cases in which accurate diagnosis before surgery is difficult. The serial changes in various diagnostic images were studied in a case of renal cell carcinoma in which definitive diagnosis could not be made by various imaging examinations and biopsies. We report on a case of renal cell carcinoma in a young adult. A 19-year old man complained of left flank pain and pyrexia. Computerized tomography (CT) scan and urography revealed a solid mass in the left kidney. Angiography revealed no abnormality, and CT scan after 3 months showed that the mass was decreasing in size, which suggested an inflammatory mass. CT scan and retorograde pyelography 12 months later showed that the tumor had enlarged and that much of the tumor had extended into the renal pelvis. Left nephrectomy was performed and histological examination revealed that the tumor was papillary renal cell carcinoma. When imaging results and clinical symptoms are atypical, pre-surgery diagnosis of renal cell carcinoma is extremely difficult. In such cases, we found that it was effective to observe the changes in various diagnostic images and to make an overall judgment based on these results.