When you see acute inflammation in the esophagus, it is most associated with GERD whereas inflammation in the stomach cardia biopsies are associated with Helicobacter infections in the majority of cases (78-98%).
Tip-offs for Helicobacter infection
Acute and chronic inflammation (biopsy looks blue at low power)
Superficial lymphoplasmacytosis
Lymphoid aggregates (often with well formed germinal centers)
Look for organisms in the mucin-rich foci (near the surface or in gland lumina)
Histo reminder: The cardia is the small segment of stomach between the distal esophagus and proximal stomach with oxyntic mucosa
Helicobacter pylori
Wide, one-and-a-half turn spiral shaped organism (has a slightly bent appearance, almost looks like a seagull)
Helicobacter Heilmannii
More slender and tightly spiraled than H. Pylori
Useful special stains:
NOTE: Special stains are NOT needed if organisms are readily apparent on H&E stain
Diff Quik: A blue stain. Look for organisms in mucin rich areas (H. pylori shown on left, H. heilmannii on right)
Warthin starry: This is a silver based stain that coats the organisms which makes them slightly larger and easier to identify than Diff-Quik stains (H. pylori shown below)
Source of Histology Images: Atlas of Gastrointestinal Pathology. Christina Arnold. Esophagus chapter- Acute esophagitis.