title: Cavitary pulmonary lymphosarcoma masquerading as rheumatoid lung disease.
mesh_terms: D001706:Biopsy; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology; D008171:Lung Diseases / Q000175:diagnosis*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000473:pathology; D008875:Middle Aged; D012216:Rheumatic Diseases; D012217:Rheumatoid Factor / Q000032:analysis
chemical_list: D012217:Rheumatoid Factor