All of the following changes are seen in dysplasia of squamocolumnar junction, except:
**Core Concept**
The squamocolumnar junction (SCJ) is a critical area where the stratified squamous epithelium of the esophagus transitions to the simple columnar epithelium of the stomach. Dysplasia at the SCJ is characterized by abnormal cell growth and maturation, which can be a precursor to invasive cancer.
**Why the Correct Answer is Right**
Dysplasia at the SCJ often involves a loss of the normal zonation and maturation of the epithelium, with abnormal cells appearing in areas where they shouldn't be. This can lead to a mixture of squamous and columnar epithelial cells, as well as the presence of goblet cells in areas where they shouldn't be (intestinal metaplasia). The SCJ also shows a loss of the normal glandular architecture and an increase in the number of mitotic figures.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because metaplasia, particularly intestinal metaplasia, is a hallmark of dysplasia at the SCJ.
**Option B:** This option is incorrect because goblet cells are indeed found in areas where they shouldn't be in dysplasia at the SCJ, as part of intestinal metaplasia.
**Option C:** This option is incorrect because the presence of dysplastic cells and loss of glandular architecture are characteristic of dysplasia at the SCJ.
**Clinical Pearl / High-Yield Fact**
A key feature of dysplasia at the SCJ is the presence of intestinal metaplasia, which can be diagnosed by the presence of goblet cells in areas where they shouldn't be. This is an important clue to the diagnosis of dysplasia and potential progression to invasive cancer.
**Correct Answer:** D