First question is are you a smoker or tobacco user ? a mass in the CT Scan
is highly suspicious of malignancy (Cancer) . You should see related expert and get your investigation done like routine blood count sputum for Gram stain and culture and sensitivity and Cytology study to know type of malignancy. You may be required to take a biopsy
or needle biopsy by CT guided as the case may be. once type and stage is confirmed treatment would be planed accordingly.