Lung nodules are abnormal spots that may show up on your lung cancer. screening scan. Doctors may call them lesions, coin lesions or solitary. pulmonary nodules (SPN). Lung nodules are very common â at least 50% of. people have them by the time they are 50 years old. The challenge is figuring. out which nodules are or will become cancer. All lung cancer starts with a nodule but 95% of lung nodules are not cancer. Nodules that are not cancer may be the result of a bacterial or fungal infection. in the past that causes inflammation and scarring in the lungs. For the small. group of people who are screened and have lung cancer, it is usually found in.