Intraoropharyngeal U-turn method using transnasal esophagogastroduodenoscopy.

The more progress that has been made in endoscopy, the more superficial cancers have been found in the head and neck regions [1–4]. There are, however, some areas that are difficult to observe on transoral esophagogastroduodenoscopy (EGD). In particular, only a tangential view of the radix linguae is obtained with transoral EGD. In this report, we present the procedure for an intraoropharyngeal U-turn method using transnasal EGD [5], which we used to diagnose a superficial squamous cell carcinoma of the radix linguae. The endoscope used (EG-580NW; Fuji Film, Tokyo, Japan) was a transnasal endoscope that was able to provide high-quality, wide-field (140°) endoscopic images that could be viewed on a monitor and digitally recorded. Suction, irrigation, and insufflation are all possible with this transnasal flexible endoscope, which facilitates clinical assessment of this particular area. The tip of the endoscope can make a U-turn up to an angle of 210° (●" Fig.1). All areas of the tongue from the radix linguae to the apex linguae can therefore be observed using this intraoropharyngeal U-turn method (●" Fig.2). The procedure for performing the intraoropharyngeal U-turn method is illustrated in●" Fig.3. The procedurewas used in a man with a superficial oropharyngeal cancer (●" Video1). First, the patient opened his mouth wide and stuck his tongue forward asmuch as possible, while making a vocal sound like “ayyy”. A tangential view of a small elevated lesion at the right radix linguae was possible on transoral endoscopy (●" Fig.4a), but closer observation was very difficult. With the endoscope inserted through the nose, the tumor was invisible on routine observation. However, by turning the transnasal endoscope through a U-turn in the oropharyngeal area, a forward view of radix linguae could be obtained. This provided a much better view of the lesion (●" Fig.4b) than had been possible with transoral endoscopy, and a 10×6-mm superficial lesion was removed by en bloc resection (●" Fig.5). Histopathological examination revealed a diagnosis of squamous cell carcinoma with microinvasion beneath the epithelium. In conclusion, the intraoropharyngeal U-turn method during transnasal EGD is a useful technique for detailed observation of the oropharynx, in particular the radix linguae.