Esophageal adenocarcinoma with enteroblastic differentiation arising in ectopic gastric mucosa in the cervical esophagus: A case report and literature review

Adenocarcinoma with enteroblastic differentiation is a subtype of alpha-fetoprotein (AFP) producing adenocarcinoma. This type of tumor is associated with a poor prognosis and is prone to metastasize. Esophageal adenocarcinoma with enteroblastic differentiation is extremely rare.The patient was a 65-year-old woman who was referred to our hospital with dysphagia. Endoscopic examination revealed an elevated lesion 20mm in diameter at 17cm from the upper incisors. Endoscopic submucosa dissection (ESD) was performed and histopathological examination revealed tubular adenocarcinoma composed of cuboidal cells with clear cell cytoplasm. Immunohistochemical stain was diffusely positive for Sall-like protein 4 (SALL4) and weakly positive for AFP and glypican 3. From this result, we diagnosed esophageal adenocarcinoma with enteroblastic differentiation. The patient is still alive without recurrence of cancer 40 months after ESD.To our knowledge, this is the first report to undergo ESD for esophageal adenocarcinoma with enteroblastic differentiation arising from ectopic gastric mucosa in the esophagus.