First I just wanted to say high, I'm technically not new to the boards but it's been quite a while since I've posted, due to taking care of my Mom who had lung-cancer. She is ok now after 3 years, and I'd just like to say thank you to the warm messages I received from the people on this board.
Now, Van, in relation to you and your situation, I can say the good news and the semi-bad news. The good news is, that from what you are telling me my guess is that it is not lung cancer either. You seem non-symptomatic for now? Is that right? So having said that, at least one symptom should be present if the mass is the size the doctors said it was. Also after a bronch, your doctor should have been able to get a good washing, and if any cancer cells were present, he should be able to tell.
Now, the bad news, there are a number of other detrimental things that can be wrong with your lungs besides lung cancer, can they have as bad an effect on the entire body? No usually the stay local to the respiratory system, but I'm not an actual doctor so I can't give you an accurate diagnosis, especially if I don't know if any symptoms are present, besides general congestion, and if all your test results are inconclusive. So in answer to your question, should you be worried, no I don't believe so, not to the point of keeping you up at night, however this could be a serious underlying issue that needs to be resolved. My advice would be to request all copies/and discs of all your current test results and bring them to get a second opinion. I don't know specifically where in the country you are located but if the answers are hazy that you are getting I'd try a specialist or a University hospital/center. Good luck and good health.