Had chest x-ray 12 days ago just got results today doctor says there's a small white patch on bottom of left lung looks like blood vessel?

Need more info: White patch could be old scar, fluid, infection, blood vessel, pneumonia, or even cancer. Where it is how big it is , the shape it is and your medical and social conditions will affect the identification process. Are you a smoker? Do you have cough? If there is low risk for infection or cancer - normally you just keep checking on the "spot: to make sure it isn;t growing.