Ultrasound found a spot on kidney could it be cancer?

Yes: Ultrasound is a very good initial screening test for the kidneys.It can help identify kidney stones, obstruction of the kidneys, and tumors. If the ultrasound is questionable or clearly abnormal, a more specific imaging study is required such as a ct scan or MRI of the kidneys for further evaluation. Lesions seen ultrasound do not necessarily indicate cancer but further testing is warranted.

Kidney: Many people have cysts. An MRI would better delineate benign or malignant.