title: Primary tracheal carcinoma: two case reports.
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000209:etiology / Q000473:pathology*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D012907:Smoking; D014134:Tracheal Neoplasms / Q000209:etiology / Q000473:pathology*