Peptic ulcer laboratory tests

Overview
The diagnosis of Helicobacter pylori can be by:
 * Breath testing (does not require EGD);
 * Direct culture from an EGD biopsy specimen;
 * Direct detection of urease activity in a biopsy specimen;
 * Measurement of antibody levels in blood (does not require EGD). It is still somewhat controversial whether a positive antibody without EGD is enough to warrant eradication therapy.

The possibility of other causes of ulcers, notably malignancy (gastric cancer) needs to be kept in mind. This is especially true in ulcers of the greater (large) curvature of the stomach; most are also a consequence of chronic H. pyloriinfection.

When observed under a microscope, the ulcer has the following presentation.

Macroscopical appearance
Gastric ulcers are most often localized on the lesser curvature of the stomach. The ulcer is a round to oval parietal defect ("hole"), 2 to 4 cm diameter, with a smooth base and perpendicular borders. These borders are not elevated or irregular as in the ulcerative form of gastric cancer. Surrounding mucosa may present radial folds, as a consequence of the parietal scarring.

Microscopical appearance
A gastric peptic ulcer is a mucosal defect which penetrates the muscularis mucosae and muscularis propria, produced by acid-pepsin aggression. Ulcer margins are perpendicular and present chronic gastritis. During the active phase, the base of the ulcer shows 4 zones: inflammatory exudate, fibrinoid necrosis, granulation tissue and fibrous tissue. The fibrous base of the ulcer may contain vessels with thickened wall or with thrombosis.