Here is a nice example of solitary renal angiomyolipoma (AML). Well-circumscribed hyperechoic lesion in the right kidney with echotexture similar to that of adjacent sinus fat. As discussed before, ultrasound cannot definitively diagnose AML, its better to obtain CT scan or MRI when in doubt. Of note, renal cell carcinomas appear hyperechoic in about one-third of cases. In our case, we had prior imaging available from ~3 years ago with no demonstrable increase in size, which is reassuring.
Old ultrasound scan
Gross appearance of AML (not our patient; from the stated reference)