What stain is used to highlight acid mucin‑containing goblet cells in intestinal metaplasia of the esophagus (Barrett’s esophagus)?

Alcian Blue Stain for Intestinal Metaplasia in Barrett's Esophagus

Alcian blue (AB) stain, typically combined with periodic acid-Schiff (AB/PAS), is the special stain used to highlight acid mucin-containing goblet cells in intestinal metaplasia of the esophagus (Barrett's esophagus). 1

Staining Characteristics

Goblet cells stain intensely blue with the Alcian blue portion of the AB/PAS stain because of the presence of acid mucins. 1, 2 This distinctive blue staining allows pathologists to:

• Distinguish true goblet cells from "pseudogoblet cells" (distended foveolar-type cells that stain for PAS but do not contain AB-positive acid mucins) 1
• Confirm the presence of intestinal metaplasia when goblet cells are rare or equivocal on routine H&E sections 1

Clinical Application and Recommendations

When Special Stains Are NOT Routinely Required

In most cases of Barrett's esophagus, intestinal metaplasia can be identified easily on standard H&E-stained sections; hence, special stains such as AB/PAS are not required routinely for histologic diagnosis. 1 The Rodger C. Haggitt Gastrointestinal Pathology Society specifically states there is insufficient evidence to justify reflexive use of Alcian blue on all esophageal biopsies. 3

When Special Stains ARE Helpful

AB/PAS staining should be reserved for select cases, particularly those in which:

• Goblet cells are rare or difficult to identify on routine sections 1
• Prominent "pseudogoblet cells" are present that may lead to overdiagnosis 1
• Histologic features are equivocal for Barrett's esophagus 1

Critical Diagnostic Pitfall

Overdiagnosis of Barrett's esophagus is common, occurring in 38% of cases by general pathologists in community practice, primarily due to misinterpretation of pseudogoblet cells as true goblet cells. 1 The AB/PAS stain helps avoid this pitfall by definitively identifying acid mucin-containing goblet cells. 1

Technical Details

• Alcian blue at pH 2.5 is the standard pH used for detecting acid mucins in goblet cells 4, 5, 6
• True intestinal-type goblet cells must be identified on routine H&E sections for confident diagnosis; positive Alcian blue staining alone without morphologic goblet cells is not sufficient 7
• Acid mucin in non-goblet columnar cells is common in both Barrett's and junctional-type epithelium and may not always indicate intestinal metaplasia 4, 5