[Ultrasonographic features of chromophobe cell renal carcinoma].

Chromophobe cell renal carcinoma is an uncommon type of renal cell carcinoma, and the number of reported cases in Japan is small. The ultrasonographic (US) features of this rare tumor are not defined. We reviewed the imaging findings of four pathologically proven chromophobe cell renal carcinomas. US, color Doppler US (DUS), computed tomography (CT) and magnetic resonance imaging (MRI) were performed preoperatively. The internal echo patterns of the tumors were homogeneous in all cases, and the lesion usually was hyperechoic even if the tumor was large, although one tumor was isoechoic. DUS revealed no color flow in any tumor. Both CT and MRI showed a relatively homogeneous, hypovascular tumor. These tumors had characteristic US findings, probably because they had a uniform growth pattern of tumor cells and none of them had necrosis or hemorrhage. When US shows a homogenously hyperechoic and hypovascular tumor of the kidney, we should suspect chromophobe cell renal carcinoma.