The stomach is part of the gastrointestinal tract. When we eat, food enters the mouth and travels down the esophagus into the stomach. Once in the stomach, the food is mixed with a strong acid which breaks the food down into very small particles. This process is called digestion. The digested food particles are then either absorbed into the bloodstream or removed from the body as waste.
The tissue on the inner surface of the stomach is made up of specialized epithelial cells that form a barrier called the epithelium. The cells at the top of the epithelium are called foveolar cells and they protect the stomach from the strong acid used to break down food. Underneath the surface epithelium is a thin layer of tissue called the lamina propria which supports the surface cells. Together, the surface epithelium and lamina propria are called the mucosa.
The most common symptoms of chronic gastritis are:
The most common cause of chronic inactive gastritis is an infection of the stomach with a bacteria called Helicobacter pylori. Infection is more common in rural areas and in the developing parts of the world. Chronic gastritis can also be seen in people who have previously been treated for Helicobacter pylori. Chronic gastritis may persist for months or even years after successful treatment.
Other causes of chronic gastritis include:
The diagnosis is usually made after a small sample of tissue is removed in a procedure called a biopsy. The tissue is then examined under a microscope by a pathologist. Your pathologist may order additional tests such as immunohistochemistry or special stains to look for Helicobacter pylori.
Chronic gastritis means that your pathologist saw an increased number of specialized immune cells called plasma cells within the lamina propria. Pathologists describe this change as chronic inflammation. The word inactive in the diagnosis means that no specialized immune cells called neutrophils were seen damaging the epithelium. Neutrophils are typically seen shortly after the injury starts and are a sign of ongoing damage.
Chronic inactive gastritis that is not treated can damage the epithelium on the inside surface of the stomach. If the damage continues for many years, the normal foveolar cells in the epithelium are replaced by cells normally found in the small intestine (small bowel). This change is called intestinal metaplasia.
Intestinal metaplasia is a non-cancerous change that develops after many years of injury. While it in itself is not cancer, it increases the risk of developing a type of cancer called adenocarcinoma over time. It is recommended that people with intestinal metaplasia undergo a follow-up endoscopic examination of the stomach at least once every three years. Biopsies should be performed at each examination.
Dysplasia is a word pathologists use to describe an abnormal pattern of growth. Dysplasia can develop in patients who have had chronic inactive gastritis for many years. It usually develops in areas of the stomach that already show intestinal metaplasia (see Intestinal metaplasia above).
Dysplasia is often described as low grade or high grade based on how abnormal the tissue looks when examined under the microscope. In low-grade dysplasia, the cells in the epithelium are darker than the normal, healthy cells. Pathologists describe these cells as hyperchromatic. In high-grade dysplasia, the normal organization of the epithelium is lost.
Like intestinal metaplasia, dysplasia is a non-cancerous change. However, it can turn into a cancer called adenocarcinoma over time. The risk of cancer is higher with high-grade dysplasia. If your pathologist sees dysplasia in your biopsy it will be described in your report.