What Could Be The Possible Cause Of Suspicious Densities Found In The Left Upper Lung On My Chest X-ray?

There are suspicious densities on left upper lung. The trachea is in the midline. The heart is not enlarged. The pulmonary vessels are within normal limits. Both hemidiaphragms are distinct. The osseous thoracic cage reveals no significant bony abnormality. Impression: Suspicious densities, left upper long Please give me some ideas what is possible cause or disease I have.