Lung Nodules that come and go

I am a 40-year-old non-smoking female.  I grew up in a smoking household until I was 18.  I have chronic airway inflammation (reason unknown) and the bronchoscopy also noted hyperemic and collapsable airway.  Bronchial levage showed mycoplasm bacteria (which I was told is insignificant) and high eosinophil count.  I also had a high serum eosinophil count.  My symptoms include shortness of breath, fatigue, and a harsh chronic cough that is constant, and frequent bronchospasms.  It is mostly nonproductive.  On occasions that I do cough up sputum it is occasionally yellow or green.  I use albuterol inhaler and nebs frequently.  I use also use steroid inhalers-Advair and Qvar.  Since December I have had two courses of oral prednisone (30 mg burst/taper)  I had a CT scan 3 months ago that revealed nodules of a ground glass appearance.  It was recommended the CT scan be repeated in 3 months and was repeated 2/22/11.  I received a brief letter today that said the original nodules have disappeared but new nodules have formed.  Could someone please tell me what this means and if I should be concerned?  Another followup CT was recommended.

Of note, cancer is prominent in my family.  My mother (a smoker) died of lung adenocarcinoma in 2000, and other cancers in my family include bowel and pancreatic.   I have a very respected pulmonologist, but he doesn't elaborate often.