Adenocarcinoma of the upper esophagus arising in heterotopic gastric mucosa: common pathogenesis with Barrett's adenocarcinoma?

Adenocarcinoma of the upper esophagus arising in heterotopic gastric mucosa is a rare tumor, with only 15 cases reported to date. We report a case in a 61-year-old man complaining of dysphagia. The upper endoscopy revealed that the tumor measured 3 cm and was 22 cm distant from the incisivors. A hiatal hernia with erosive esophagitis of the distal esophagus was present. On microscopic examination the tumor corresponded to a poorly differentiated adenocarcinoma immunoreactive for cytokeratin (CK) 7 and p53. The surrounding heterotopic gastric mucosa contained foci of intestinal metaplasia immunoreactive for CK7 in the surface epithelium and the entire glands and CK20 in the superficial epithelium and superficial glands. The CK7 and p53 positivity that we observed is very common in Barrett's adenocarcinomas. Moreover, intestinal metaplasia in heterotopic gastric mucosa shows the same CK7/CK20 pattern as specialized Barrett's mucosa. These common features shared by adenocarcinomas of the upper esophagus arising in heterotopic gastric mucosa and adenocarcinoma of the lower esophagus developing on Barrett's mucosa suggest that those two types of cancer have a common pathogenesis, related to gastroesophageal reflux disease.