title: Mass lesions on chest x-ray film.
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011859:Radiography