Gastrointestinal: Esophageal adenocarcinoma arising from circumferential ectopic gastric mucosa: A case report

A 59-year-old man was referred to our institution for the treatment of esophageal adenocarcinoma. Esophagogastroduodenoscopy (EGD) revealed circumferential ectopic gastric mucosa located 19–23 cm from the incisors (Fig. 1a). Moreover, a 20-mm-sized protruded reddish tumor with a slightly elevated lesion around it was found on the circumferential ectopic gastric mucosa (Fig. 1b,c). Because the whole lesion was soft and the protruded lesion did not have an expanding appearance, we diagnosed the lesion as an intramucosal cancer and performed endoscopic submucosal dissection (ESD). En bloc resection was successfully achieved (Fig. 1d). The resected specimen size was 53 × 34 mm, and contained 44 × 26 mm of tumor (Fig. 1f). The mucosal defect was more than three-quarters of circumference. Injection of triamcinolone and shielding with polyglycolic acid (PGA) sheets and fibrin glue were performed to prevent stenosis after resection of the lesion as the mucosal defect was more than three-quarters of circumference. Histopathological analysis showed that well-differentiated tubular adenocarcinoma was dominant in the heterotopic gastric mucosa, pT1a-MM, ly(-), v(-), pHM0, and pVM0 (Fig. 2a–d). The ectopic gastric mucosa in the background of the tumor consisted of slightly atrophic gastric fundic gland tissue. There was only small amount of intestinal metaplasia at the margins, and the number of infiltrated cells was small overall. The follow-up EGD showed that the glandular epithelium was replaced by squamous epithelium at the ulcer scar, which was confirmed by biopsy (Fig. 1e). The frequency of upper esophageal ectopic gastric mucosa is about 10%, and only two cases of them (0.3%) were more than two thirds of esophageal circumference. Therefore, esophageal adenocarcinoma arising from the circumferential ectopic gastric mucosa is quite rare, and only approximately 60 cases have been reported. This is a valuable example of a case that could be treated by ESD.