It's "good" that you have bronchitis right now for 2 reasons.
One being, this could very well be what this spot is related to. It's very easy to misread an x-ray of the lung, not because doctor's are too dumb to read them but more because it's a rudimentary tool nowadays with MRI's, CT scans and the like and moreso because the incidents of false positives on lung x-rays is pretty high.
Second being, that you'll get to find out what this is if it is something. It's alway's better to catch any kind of thing early. I know it's hard not to worry so I won't even tell you not to. If you smoke, quit now. This may just be the incentive you need. If you don't smoke that's even more good news because lung cancer is pretty rare in someone who doesn't smoke.
Boy, oh boy does this ever bring back memories for me. In April, 1995, I went in for a routine X-Ray. I'll never forget that day for the rest of my life. Yea, just like you they found a spot about the same size as you describe on my lung. I thought " what does this mean?" Well, I kept getting told the same thing maybe something maybe nothing. I went from Doctor to Doctor...they all told me the same thing that the only way to find out for sure is to have a biopsy (translation surgery) was I scared...you have no idea. They wanted to cut into me. I never smoked they told me this was good for me. THe odds of it being cancer were greatly diminished. So I kept going from doctor to doctor, I think I saw about 3 surgerons and several pulmonary specialists in Dallas, Ft. Worth Texas. I asked one doctor how long I would have if it was cancer. He said "well, in a non smoker like you it generally spreads like wildfire you'll probably be dead in 6 months. Oh, man I went out and got a will drawn up, would walk in to look at my kids at 3 oclock int he morning I was living a living hell. I couldn't sleep...I had to know but I didn't want surgery...I just kept looking for an opinion that would be what I wanted to hear. But I think all the surgeons wanted to be absolutely sure to keep from a lawsuit. I know I know your dying to know what happened right! Well it was histoplasmosis (the cave illness). People who go into caves get it a lot. I'd been in 3 including Carlsbad and 2 down in San Antonio. Histoplasmosis as I understand it is acquired from plant vegetation and decaying bird droppings. It is most prevalent in the Ohio and Mississippi river valleys's But I had it in Texas. But I also had done traveling to New Orleans and Omaha, Nebraska (two hot beds for histoplasmosis) I'm also told that something like 80% of the people in Kentucky have antibodies for Histoplasmosi in their system. I heared all kinds of stories about this and that but finally they gave me an fungus test where they send the specimen to the Mayo lab and grow it for a week and it came back I had acute antibodies for Histoplasmosis. Can I help answer any other questions?