RT Journal Article SR Electronic T1 Airway obstruction caused by retro-laryngeal carcinosarcoma JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e230302 DO 10.1136/bcr-2019-230302 VO 12 IS 5 A1 Yasuyuki Chida A1 Ryota Inokuchi A1 Hiroaki Kikuchi A1 Kazuaki Shinohara YR 2019 UL http://casereports.bmj.com/content/12/5/e230302.abstract AB