Case of pharyngeal cancer not detected during preoperative transoral endoscopy with narrow band imaging.

We herein report a case of pharyngeal cancer that was not detected during preoperative transoral endoscopy with narrow band imaging (NBI). A 61-year-old female was referred to our hospital for further evaluation of a pharyngeal lesion. Endoscopy revealed a small, elevated lesion, approximately 7 mm in size, at the right pyriform sinus. We performed endoscopic resection to remove this lesion under general anesthesia based on the biopsy results. Intraoperatively, we detected another tumor in the left oropharyngeal wall with Lugol staining after insertion of a curved laryngoscope. Although this lesion was ≥20 mm in diameter, we were unable to detect it during preoperative transoral endoscopy with NBI and white light imaging. We performed endoscopic treatment for this lesion 2 months later. The pathological diagnosis was pharyngeal cancer; the lesion had low vascularity. This case report provides an example of false-negative endoscopy with NBI. Although transoral endoscopy with NBI has improved the early diagnosis of superficial squamous cell carcinomas of the head and neck, pharyngeal cancers that are less vascular may be missed with NBI.