Abstract
A left lung mass after induction and tracheal intubation, which partially was obstructing the left main bronchus, was accidentally discovered in a 56-year-old female scheduled to undergo elective total thyroidectomy. Her preoperative chest X-ray showed a right-sided shift of the trachea. She did not have stridor or shortness of breath or superior vena cava obstructive syndrome. Induction and tracheal intubation were performed uneventfully. Fiberoptic bronchoscopy performed and showed complete obstruction on the left main bronchus. Excision biopsy suggested mucoepidermoid carcinoma (MEC). MEC is one of the very rare neoplasms of the lungs. Most lesions are low grade and overall prognosis may be more favorable than other forms of lung cancer.