title: Trifurcation: an unusual variant of the left main stem bronchus.
authors.affiliation: Cleveland Clinic Foundation Cleveland, OH.
authors.forename: Danai
authors.initials: D
authors.lastname: Khemasuwan
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Culver
mesh_terms: D000368:Aged; D063405:Anatomic Variation; D001980:Bronchi / Q000002:abnormalities*; D001999:Bronchoscopy; D005260:Female; D006801:Humans; D012507:Sarcoidosis / Q000175:diagnosis*