Magnetic resonance scanning of the upper airway following difficult intubation reveals an unexpected lingual tonsil.

We present a case of a 40-year-old woman requiring elective surgery who had an unexpected Grade 4 Cormack and Lehane laryngoscopy view. Both curved and straight laryngoscope blades in the sniffing and hyperextended head and neck positions were used. Endotracheal intubation was accomplished with some difficulty using a No. 3 Macintosh blade and Frova intubating catheter in the sniffing position. The cause of the difficult laryngoscopy was a lingual tonsil as shown in postoperative magnetic resonance scans. We feel that a comprehensive postoperative evaluation should be conducted after every difficult laryngoscopy (Cormack and Lehane Grade 3b and 4). The use of magnetic resonance imaging may provide important objective information for both the anaesthetist and the patient, allowing a better understanding of causes and possible solutions for future airway management.