Could Small Thickening On The Lung Be Malignant?

Because I had significant pain in the center of my upper back, I had a CT scan of my thoracic spine which shows the spine is ok, but a small thickening in my lung was discovered. I will be having another CT scan of my lungs. How likely is it to be from infection? scar tissue? benign? cancer? I ve always been a non-smoker, worked in an office, overweight by 40 lbs, 68 yrs old. Only known exposure to asbestos was 50 years ago for a few hours when I heat treated (in home oven) some tools for my tool & die maker husband. Family history, father was smoker had lung cancer as did his brother. His half brother had throat cancer, sister had stomach cancer and another sister died at 12 years old from brain tumor unknown if cancer. Mother passed from congestive heart failure and pneumonia. I haven t had a cough or any respiratory issues other than an occasional cold.