Endoscopic submucosal dissection for superficial esophageal cancer in a diverticulum: A case report with literature review.

Superficial esophageal cancer (SEC) in a diverticulum is rare and has a high risk of perforation during endoscopic resection. Although endoscopic submucosal dissection (ESD) is a standard treatment option, it is challenging to perform. Here, we describe the case of a 79-year-old male patient with a history of ESD for SEC. Surveillance esophagogastroduodenoscopy identified a 20-mm-sized reddish depressed lesion in a diverticulum in the middle esophagus. The lesion was confirmed to be squamous cell carcinoma by biopsy. Magnification endoscopy with narrow-band imaging showed intraepithelial papillary capillary loops of type B1 according to the magnified endoscopic classification of the Japan Esophageal Society. Endoscopic ultrasonography revealed the presence of the muscular layer of the esophagus wall in the diverticulum. Therefore, the lesion was diagnosed as SEC, confined to the epithelium or lamina propria mucosae, in a Rokitansky diverticulum. Based on these findings, ESD was considered technically feasible. Traction-assisted ESD using clip with line was performed, and en bloc resection was achieved without adverse events. The resected specimen pathologically revealed a squamous cell carcinoma confined to the lamina propria mucosae without lymphovascular invasion, suggesting a curative resection. The patient recovered well, and no recurrence has been observed for 5 years after the ESD. Whether ESD is appropriate for the treatment of SEC in a diverticulum remains unclear. However, our case shows that it can be a treatment option in such cases due to its minimal invasiveness and good effectiveness.