Background/Aims: Image-enhanced endoscopy can detect superficial oro-hypopharyngeal squamous cell carcinoma; however, reliable endoscopy of the pharyngeal region is challenging. Endoscopy under general anesthesia during transoral surgery occasionally reveals multiple synchronous lesions that remained undetected on preoperative endoscopy. Therefore, we aimed to determine the lesion detection capability of endoscopy under general anesthesia for superficial oro-hypopharyngeal squamous cell carcinoma. Methods: This retrospective study included 63 patients who underwent transoral surgery for superficial oropharyngeal squamous cell carcinoma between April 2005 and December 2020. The primary endpoint was to compare the lesion detection capabilities of preoperative endoscopy and endoscopy under general anesthesia. Other endpoints included the comparison of clinicopathological findings between lesions detected using preoperative endoscopy and those newly detected using endoscopy under general anesthesia. Results: Fifty-eight patients (85 lesions) were analyzed. The mean number of lesions per patient detected was 1.17 for preoperative endoscopy and 1.47 for endoscopy under general anesthesia. Endoscopy under general anesthesia helped detect more lesions than preoperative endoscopy did (p<0.001, paired t-test). The lesions that were newly detected on endoscopy under general anesthesia were small and characterized by few changes in color and surface ruggedness. Conclusions: Endoscopy under general anesthesia for superficial squamous cell carcinoma is helpful for detecting multiple synchronous lesions.

Objectives Recent innovations in prophylactic treatment with steroids have overcome the issue of esophageal stricture after endoscopic submucosal dissection (ESD), except in entire circumferential esophageal squamous cell carcinoma (EC‐ESCC). Current Japanese guidelines weakly recommend performing ESD for clinical epithelial/lamina propria EC‐ESCC with a longitudinal extension <50 mm upon implementing prophylactic treatment against stricture. However, the accurate indications for ESD in EC‐ESCC remain unknown, and strategies differ among institutions. The aim of this study was to understand the initial treatment strategy for EC‐ESCC and prophylactic treatment after ESD against esophageal stricture. Methods A questionnaire survey was conducted across 16 Japanese high‐volume centers on the initial treatment for EC‐ESCC according to the invasion depth and longitudinal extension, and prophylactic treatment against stricture. Results ESD was performed as the initial treatment not only in clinical epithelial/lamina propria lesions <50 mm (88–94% of institutions), but also in clinical epithelial/lamina propria ≥50 mm (44–50% of institutions) and clinical muscularis mucosae/SM1 (submucosal invasion depth invasion within 200 μm) lesions <50 mm (56–75% of institutions). Regarding prophylactic treatment against esophageal stricture, although there was a common point of local steroid injection, the details and administration of other treatments varied among institutions. Conclusions As ESD was performed with expanded indications for EC‐ESCC than those recommended by the guidelines in more than half of the institutions, the validity of ESD for expanded EC‐ESCC needs to be clarified. For that, it is necessary to prospectively collect short‐ and long‐term outcomes after ESD and other treatments, including esophagectomy or chemoradiotherapy.