This medical presentation details the comprehensive management of lung cancer, beginning with the critical distinction between pulmonary nodules and masses. It highlights how imaging characteristics, such as size and spiculated borders, help clinicians categorize lesions as benign or malignant. The text identifies tobacco use as the primary risk factor while also exploring environmental triggers like radon and asbestos exposure. Patient case studies illustrate the shift from asymptomatic incidental findings to advanced clinical presentations featuring weight loss and hemoptysis. Finally, the source outlines essential diagnostic procedures, including CT scans and biopsies, alongside national screening guidelinesdesigned to improve survival through early detection.