title: Roentgenogram of the month. Rapidly developing mass in an asymptomatic man.
mesh_terms: D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging*; D002813:Chondrosarcoma / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D011859:Radiography; D013249:Sternum / Q000000981:diagnostic imaging; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging*