Barrett Esophagus
Barrett’s esophagus is a classic example of metaplasia, where the normal stratified squamous epithelium of the distal esophagus is replaced by specialized columnar epithelium with goblet cells due to chronic gastroesophageal reflux disease (GERD).
1. Pathogenesis & Risk
- Chronic Irritation: Persistent acid exposure induces the change from squamous to columnar cells to better withstand the acidic environment.
- Malignant Potential: It is a well-recognized precursor to esophageal adenocarcinoma. The progression follows the sequence: Metaplasia → Dysplasia → Adenocarcinoma.
2. Histological Diagnosis
| Finding | Significance |
|---|---|
| Goblet Cells | The hallmark histological feature required for the diagnosis of Barrett’s esophagus. |
| Columnar Metaplasia | Replacement of the protective squamous lining. |
3. Exam Must-Knows
- Surveillance: Patients with Barrett’s esophagus require periodic endoscopic surveillance with biopsies to monitor for the development of dysplasia.
- Clinical Clues: A patient with a long-standing history of heartburn/GERD who develops new, progressive dysphagia or unintentional weight loss should be immediately evaluated for esophageal cancer.
Pathology Board Hint: For board questions, always remember that Adenocarcinoma typically arises in the distal 1/3 of the esophagus (associated with Barrett/GERD), whereas Squamous Cell Carcinoma is more common in the middle 1/3 (associated with smoking and alcohol).