Papillary renal cell carcinoma: CT and sonographic evaluation.

The CT, sonographic, and pathologic appearances of 13 surgically confirmed cases of papillary renal cell carcinoma were reviewed. CT-pathologic correlation was available in all 13 cases. Sonography was performed in eight patients (10 distinct renal masses). CT features closely correlated with the previously established clinicopathologic and angiographic appearances. Papillary renal cell carcinoma demonstrated low stage at presentation in most cases (10 of 13 had stage I or II), had a high frequency of calcification (seven), and had less enhancement (diminished vascularity) than typical hypernephroma on CT scans. No consistent sonographic pattern existed; one of 10 masses was hyperechoic, five were hypoechoic, and four were isoechoic compared with normal kidney cortex. On the basis of these observations, a prospective CT diagnosis of papillary renal cell carcinoma can be confidently made in many circumstances. This is particularly important when renal-sparing surgery is a clinical consideration.