Brian, I hope you look back in as I can relate and have had experience in this.
In all such discoveries, further testing should be done IMHO an din general medical sense too. These growths can of course be one of many different diagnosis, and no peace of mind can be foudn until actually finding out what they are (it is).
LOng term smokers often get "cysts" in the lungs. Many times it is benign and has no definite connection to cancer, but at the same time that does not promise assurance that they will not turn so later.
I had a growth in the right lower lobe of my lung, and subsequent testing showed it free and clear, and its growth rate was really slow over two years, but it was growing.
I just had it removed last month through minimally invasive surgery with robotics that are widely available in major hospitals now. Once taken out, another post-op biopsy proved it to be T1a stage cancer and they got it all.
But if you are looking for advice, get a primary care MD to refer your mom for a biopsy, and an enhanced CAT scan.. If she has more than one growth then that biopsy is important. Most important is that she does nothing. Waiting in the wrong scenario could make that non-lethal event of an early stage carcinoma into a fatal stage. Its not going to turn and change overnight but surely schedule an enhanced CAT and a biopsy. Make sure it is a reputable hospital and radiology/cancer center, as a botched biopsy can either miss or burst a cyst with unpleasant results.
IMHO opinion, and probably you will be told so by the MD you get, CAT scans every six months or at least x-rays, will determine if the tumor (we can call it growth for now as tumor is a scary word to many) is growing or not. If it grows, then certainly there is cause to take a more direct approach. If it remains the same size or shrinks, then it probably isn't a worry.
Added for the extra info, although doctors do not preach on it, electronic cigarettes are inexpensive and far better for a cigarette smoker than the cancer sticks are, especially if a person is a heavy smoker. You can actually see and feel the difference, cleared up lungs becoming obvious, in as little as two to four weeks, with major improvements at 6 months, 1 year and 3 years. I smoked e-cigs now for 3 years, and lately have been on "Chantix" smoking intervention deterrent medications for 3 months. I never could quite put down the cigs flat out. So I have used these help devices to better my lungs and thus my life.
Get her to an MD though for the biopsy and CAT referrals as you cannot schedule them yourselves. And be sure to support your mom through it as most people even if they act like it is nothing to worry about, down deep inside they worry no matter. There is a great weight lifted off you when you find out it is not cancer or that they got all of it.
I have to have CAT scans once every 6 months for 2 years, then once every year for 3 years to make sure there is no recurrence but I feel much brighter about my future, and as I said, it may well be cigarette related cysts. But most all of all, do not do nothing! :)
click on link and read here please:
And don't freak out, its not a worse case scenario for your mom (smiles here).
(copy paste if not clickable)
https://www.researchgate.net/publication/51057298_A_Young_Man_with_Multiple_Pulmonary_Cysts
Sorry, that sentence was supposed to read "most important is that she does not do nothing" in paragraph #5, they don't have "edit" options here. :)