2.2 Examination methods of vocal cord leukoplakia
In this study, the EVIS LUCERA 260 system and BF-260 electronic endoscope by Olympus were used to observe vocal cord leukoplakia. The examinations of all patients were performed by one experienced laryngologist who did not participate in the subsequent evaluation. Patients were examined in the supine position. The laryngoscope was inserted through the nasal cavity to observe the nasopharynx, oropharynx, hypopharynx, and larynx. When vocal cord leukoplakia was observed, the laryngeal mucosa was sprayed with 2% lidocaine for surface anesthesia. Representative images were collected before biopsy of the vocal cord leukoplakia. The biopsy specimens were preserved in 10% formalin and submitted for pathological examination.