Prevalence and significance of pancreatic acinar metaplasia at the gastroesophageal junction

Pancreatic acinar metaplasia (PAM), defined as nodules of glandular tissue forming acini composed of cells with coarse apical eosinophilic granules, with or without mucous cells, was recently recognized in gastric mucosa, but its significance is not known. As part of a study on intestinal metaplasia at the gastroesophageal junction (GEJ), we evaluated the prevalence and clinical and histologic correlates of PAM in biopsy specimens from the gastroesophageal squamocolumnar junction. All adult patients having elective upper gastrointestinal endoscopy over a 6-month period were invited to participate. Clinical data and endoscopic findings were recorded. Biopsy specimens, obtained from both sides of the apparent squamocolumnar junction, were processed routinely and reviewed (without knowledge of the clinical data) to evaluate types of epithelium, types and degree of inflammation, and the presence of PAM. The presence or absence of PAM was then correlated with the other histologic findings and with the clinical and endoscopic data. The study comprised 155 patients (79 women, 76 men; 139 white patients, nine black patients, and seven patients of other ethnic groups). Their mean age was 52 years (range; 18-89 years). PAM was present in 37 patients (24%). PAM was not associated with any of the reported symptoms, endoscopic evidence of esophagitis or columnar epithelium in the distal esophagus, or any of the histologic features evaluated, including active esophagitis, intestinal metaplasia at the GEJ, active and chronic gastritis, intestinal metaplasia in the stomach, and Helicobacter infection. Although PAM is present in a considerable proportion (24%) of patients with mucosal biopsy specimens from the squamocolumnar junction, it appears to be an incidental finding unrelated to clinical or histologic abnormalities. We therefore suggest a congenital, rather than an acquired, origin for this entity.