Esophageal superficial adenosquamous carcinoma resected by endoscopic submucosal dissection: A rare case report.

Background: Adenosquamous carcinoma (ASC), which is comprised of squamous cell carcinoma (SCC) and adenocarcinoma elements, is a rare histological type of esophageal carcinoma. Few reports have focused on the endoscopic findings and the effectiveness of the endoscopic treatment of early ASC.

Case Summary: A 77-year-old man underwent esophagogastroduodenoscopy for heartburn. A flat lesion with an uneven and slightly elevated central portion was found in the distal esophagus. Magnifying endoscopy with narrow-band imaging showed a well-demarcated brownish area with dendritically branched abnormal vessels and highly irregular intrapapillary capillary loops. A histopathological diagnosis of SCC was obtained by endoscopic biopsy. Endoscopic ultrasonography revealed a hypoechoic mass confined to the mucosa layer. The lesion was suspected to be SCC with invasion into the muscularis mucosa. The lesion was resected by endoscopic submucosal dissection and histologically diagnosed as esophageal ASC limited within the muscularis mucosa, which was completely resected without lymphovascular or neural invasion. The SCC element was the pre-dominant element. The adenocarcinoma element formed ductal and nested structures distributed in a focal pattern. The patient underwent only endoscopic submucosal dissection and has been under annual endoscopic and radiographic surveillance for 3 years without recurrence.

Conclusion: For early ASC confined within the mucosal layer, complete endoscopic resection might also be a curative treatment.