Tools to diagnose and classify gastric conditions

The different types of gastritides and gastropathies are characterized by various combinations of histological changes, many of which are expressions of immune, inflammatory, and adaptive responses common to several conditions. However, the presence, absence, and relative intensity of these responses provide important etiologic clues and are crucial in the categorization of the process. These histological changes can be viewed as the foundations for the terminology of gastritis, and some familiarity with them is indispensable to understand both the classification and the related manifestations of nonneoplastic gastric conditions.

Epithelial Degeneration

Surface epithelial degeneration is a nonspecific response to injury seen in all forms of gastritis. It is most conspicuous in chemical gastritis and H.pylori gastritis. In H.pylori gastritis, the intimate contact of bacteria with the surface cell membrane makes epithelial degeneration particularly prominent. Cell injury and necrosis can lead to erosions, which are seen endoscopically either as flat superficial lesions or as elevated lesions whose chronic nature is suggested by polypoid regenerative mucosa at the margins. The former are often the result of acute damage caused by drugs, bile reflux, or ischemia, whereas the latter are almost always associated with H.pylori gastritis.

Foveolar Hyperplasia

Elongation and increased tortuosity of gastric pits result from hyperplasia of the foveolar cells, a presumed adaptive response to increased cellular exfoliation from the surface epithelium. It can be viewed as a visual surrogate for increased epithelial cell turnover. Hyperplasia is accompanied by hyperchromatic nuclei and mitotic activity reaching an increased height of the pit and by other signs of cellular immaturity, such as mucin depletion and a high nucleocytoplasmic ratio. Marked foveolar hyperplasia is a prominent feature of chemical injury, but lesser degrees are commonly seen in H.pylori gastritis.

Hyperemia and Edema of the Lamina Propria

Mucosal hyperemia—often visible endoscopically—is considered to be an indicator of bile reflux gastritis, and a significant correlation has been found with the concentration of bilirubin in gastric juice. Histologically, marked edema of the lamina propria with minimal inflammation is a characteristic finding in bile gastritis.

Дата добавления: 2015-11-14