Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Your renal scan show that you are having renal stone in left kidney which is not causing any obstruction in urinary flow, there is nothing serious in this report except a harmless renal stone, no chance of having any renal cancer in this report, if you are not having any lower back pain or recurrent UTI then i would suggest you to get let it go and get your ultrasound repeat after 3 months to see if the renal stone has increased in size or causing and obstruction. Hope I have answered your query. Let me know if I can assist you further.