A 5 mm nodule is considered quite small. The odds are high, and in your favor, that a nodule this small, especially one with a smooth, round border, is a benign lesion. That would be especially true if you are a non-smoker. Depending on smoking history, geographic location for example mid-west or southwest, your age, the radiologic density of the nodule and the presence or absence of this nodule on previous x-rays, your doctor, especially if he/she is a lung specialist, working with a chest radiologist, should be able to provide informed speculation on the nature of this lesion. It is very important that they review all previous chest x-rays and, if any, previous CT scans.
A nodule this size does not lend itself well to a number of diagnostic techniques, including thin needle biopsy/aspiration. Skin tests and serological testing are non-diagnostic and, hence, useless. Unless there is one or more specific features of this nodule to suggest cancer, your doctors will probably recommend a period of waiting, with a repeat CT scan in 3 to 6 months.
You may wish to discuss the above with your doctors.
Good luck.
Well I did smoke for about 4years then I quit and I have been smoke free for 9 years.When I was around 13 I had pneumonia could that maybe caused scar tissue on my lung?