Histopathology of pancreatic acinar cell metaplasia in Barrett's esophagus

The presence of pancreatic acinar cell metaplasia (PACM) at lower esophageal biopsies is a particular histopathological finding.

Aims: To assess the frequency of PACM among patients suffering from Barrett's oesophagus (BE) and to determine the coincidence of PACM with other columnar metaplasias.

Materials and methods: Between 2000 and 2005, 380 biopsy samples obtained from 300 patients having endoscopic and histopathologic evidence of BE were examined using conventional (Hematoxilin-Eosin, Periodic Acid Schiff-Alcian Blue pH=2.5, Gomori's Aldehyde Fuschin-Alcian Blue, Giemsa) and immunohistochemical (Alpha-1-antitrypsin, Lysozyme) stainings.

Results: In five percents of the specimens (20 out of 380; male/female ratio=0.6; median age: 58) PACM was identified in association with cardiac, fundus (oxyntic), mixed cardiac-oxyntic and intestinal mucosa in 7, 2, 3 and 8 cases, respectively. Periodic Acid Schiff-Alcian Blue and Gomori's Aldehyde Fuschin-Alcian Blue stainings highlighted secretory granules in both apical and basal portion of the pancreas acinar cells thus they helped with the differentiation between pancreas acinar cell and paneth cell metaplasia. Immunohistochemically, alpha-1-antitrypsin and lysozyme stainings showed consistent positivity in metaplastic exocrine pancreas acini.

Conclusion: Although the genesis of PACM appears to be unclear, the precise evaluation of lower oesophageal biopsies significantly contributes to obtain data about the pathogenesis of BE.