The stomach is composed of several anatomic zones. Moving proximal to distal, like a piece of food, you pass (1) the gastroesophageal junction, (2) the cardia, (3) the fundus or body, (4) the antrum, and (5) the pylorus (Table 7.1 and Figure 7.1). For the pathologist, there are essentially two types of mucosa in the stomach (Figure 7.2), antral and oxyntic, as cardiac mucosa looks very similar to antrum. The entire stomach epithelium is composed of pits (invaginations from the surface) and glands (deep to the pits). The surface and pits are lined by columnar mucinous epithelium (sometimes called foveolar type) which stains bright pink with PAS/AB. The regions of the stomach are divided by the type of underlying glands:
Antral mucosa (found in the antrum): The glands are loosely packed, mucinous, and occupy about half of the epithelial thickness. Cardiac mucosa looks very similar.
Oxyntic mucosa (found in the fundus or body): The glands are tightly packed, contain granular parietal (pink, acid-secreting) and chief (purple, enzyme-secreting) cells, and occupy three fourths of the mucosal thickness.
Transitional mucosa: Features of both antral and oxyntic are present. Transitional mucosa represents the overlap zone.
It is important to note what kind of epithelium is present in the biopsy tissue so that the endoscopists can correlate with what they saw. Also, there are certain processes that differentially affect mucosal types; clarifying the type of epithelium involved may change the differential.
Endocrine cells occur singly in the glands. In the body, they are mainly enterochromaffinlike cells, while in the antrum they are mixed gastrin, enterochromaffin, and somatostatin. A chromogranin stain highlights all endocrine cells. A gastrin stain should be positive only in the antrum.
KeywordsCeliac Disease Lamina Propria Intestinal Metaplasia Oxyntic Mucosa Pylorus Gastritis
Unable to display preview. Download preview PDF.