A patient with chronic gastroesophageal reflux disease developed Barrett’s esophagus. Microscopy of this region of esophagus shows:
**Core Concept**
Barrett's esophagus is a complication of chronic gastroesophageal reflux disease (GERD) characterized by metaplastic changes in the esophageal mucosa, resulting in the replacement of the normal squamous epithelium with a columnar epithelium. This transformation occurs in response to prolonged exposure to acid and bile reflux.
**Why the Correct Answer is Right**
The correct answer is intestinal metaplasia, which is a hallmark of Barrett's esophagus. This change involves the replacement of the normal squamous epithelium with a columnar epithelium that resembles the intestinal mucosa, with goblet cells being a key feature. The intestinal metaplasia is thought to be a result of the repeated exposure to acid and bile reflux, which leads to chronic inflammation and eventual replacement of the normal epithelium.
**Why Each Wrong Option is Incorrect**
**Option A:** Squamous metaplasia is incorrect because Barrett's esophagus involves the replacement of squamous epithelium with columnar epithelium, not the other way around.
**Option B:** Ciliated columnar epithelium is incorrect because the columnar epithelium in Barrett's esophagus is not ciliated and does not resemble the respiratory epithelium.
**Option C:** Pyloric gland metaplasia is incorrect because while this can occur in the stomach, it is not a characteristic feature of Barrett's esophagus.
**Clinical Pearl / High-Yield Fact**
It is essential to recognize Barrett's esophagus, as it is a precursor to esophageal adenocarcinoma, and patients with this condition require regular surveillance and monitoring for dysplasia and cancer.
**Correct Answer:** C.