A prospective study of endotracheal tube cytology in head and neck cancer patients.

: A prospective study was undertaken to determine the incidence of endotracheal tube contamination by malignant cells in patients with head and neck cancer undergoing bronchoscopy. In 67 consecutive patients, bronchoscopy was performed with a flexible instrument, through or beside the endotracheal tube. Following the procedure, the inside and outside of the tube were washed and the specimens examined cytologically. Fifteen positive (class III to V) cytologic specimens were obtained, all from the outside of the tube. All washings from inside the tube were negative (class I and II). Twelve of the positive cytologic specimens were found in patients with hypopharyngeal and laryngeal carcinoma, two with carcinoma in the tongue base, and the other primary site was unknown. Two patients with normal chest roentgenograms had positive bronchial and endotracheal tube washings. In both the bronchoscope was passed beside the endotracheal tube. This study provides additional evidence that contamination of the bronchoscope can occur when it is passed directly over a carcinoma of the head and neck.