Welcome, John, to Mayo Clinic Connect. I'm sorry that it has taken me so long to respond. It is indeed harrowing to learn that something unexpected is growing in your body. The only thing that I can tell you is that to take one thing at a time. I don't know much about your medical history so I have a couple of questions to help me know what is going on.

First, I am a 24-year lung cancer survivor with a history of many treatments. I have had 2 types of lung cancer. I am treated at a major teaching hospital in Boston.

What brought you to getting care for a doctor's visit? Many lung lesions under 9mm are not considered cancerous. There are different types of cancer and having a CT scan is the first scan that will help determine what is going on in your chest. I glimpsed a hint that you are on an antibiotic and already have a CT planned?

What is the date of your CT? If you have an infection then it should pretty much show up an improvement. If there is something else going on that is not based on a bacteria then further testing is needed, hence the CT scan.

I agree with Sue that having your sputum tested is a good idea. Have you had this done?

I smoked for 35 years. Smoking is the leading cause of lung cancer but if you have lungs you can get lung cancer.

WHat kind of doctor is ordering the tests? DO you know him/her and do you like him/her?