Yes, it can be something other than cancer. Other types of infections such as fungal infections, atypical mycobacteria, and other unusual infections may not respond to typical antibiotics. Other auto-immune diseases diseases such as vasculitis, rheumatoid arthritis, sarcoidosis, etc. can cause masses on a chest x-ray. However if there was something seen on chest x-ray and antibiotics are not making you feel better, a CT would be indicated. If antibiotics do make you feel better, then the chest x-ray should be repeated in 6 to 8 weeks and if the abnormality is still present a CT scan should be performed.

Justin Thomas