Objective:

To investigate the ultrasonographic manifestations of renal oncocytoma（RO）.

Methods:

Analyzed the ultrasonographic findings of 22 patients with RO confirmed by surgical pathology. Summarized the characteristics of ultrasound images. It included tumor location

size

morphology

boundary

internal echo

blood supply characteristics and contrast-enhanced ultrasonography.

Results:

RO was located in unilateral kidney in 22 patients. 17 cases had equal echo or high echo

and 3 tumors showed radially hypoechoic interior. 7 cases showed posterior echo enhancement

6 cases were hyperechoic. Rich or more

abundant of color blood flow was in 17 cases. 6 cases did contrast-enhanced ultrasound examination

6 cases were syndichously enhanced with the renal cortex. At the peak

2 cases presented slightly low echo

4 cases showed isoecho

radially unenhanced areas were always observed in 1 case. In the parenchymal stage

fast wash-out was displayed in 3 cases

isochronously wash-out in 1 case，delay washout in 2 cases，2 cases of them displayed pseudocapsule echo in the delay.

Conclusion:

Most RO tumors are isoecho with clear boundaries or rich blood supply tumor with slightly higher echo. The echo behind the tumor can be enhanced

and central radial scar can be seen inside. Contrast-enhanced ultrasound is mainly synchronous uniform enhancement with rapid decrease

equal or low echo at peak

pseudo capsule can be seen in parenchymal phase

and radially unenhanced area can be seen inside.