Contents



Preface

The functional role of the esophagus is motility, which is the motion that advances liquid and solid foods from the mouth to the stomach; there is no secretion activity. The term esophagitis refers to all inflammations and irritative effects on the esophageal mucosa. Common causes include acid gastric reflux, side effects of some medications, bacterial or viral infections, ingestion of strong acid or alkali solutions or solid substances, and so on. The clinical appearance of esophagitis can be characterized by heartburn, dysphagia, odynophagia, cough, nausea, vomiting, chest pain, or sore throat. In general, esophagitis, if untreated, can cause esophageal ulcers followed by scarring and narrowing or neoplastic degeneration. Acid reflux leads to gastroesophageal reflux disease, which is a complex clinical condition with some mucosal esophageal lesions with increasing severity (Barrett's esophagus). Usually, infectious esophagitis, by bacteria, viruses, fungi, or parasites, can occur in patients with weakened immune systems. Eosinophilic esophagitis is based on the excessive response to some allergens (milk, eggs, peanuts, etc.). The expression "gastritis" is the more discussed and ambiguous diagnostic definition of gastric clinicopathological conditions. In the current medical language, there is confusion regarding the definition of this pathology because the term "gastritis" is currently used indifferently for symptoms in the upper gastrointestinal (GI) tract or for endoscopic aspects and histological characteristics that can be referred to as gastric mucosal phlogosis, erosion, hemorrhagic lesions, or injury. We must remember that inflammation of the gastric mucosa should not present symptoms in the upper GI tract. Clinical and instrumental exams provide data that are difficult to correlate with each other. The symptoms that can be referred to as esophagogastroduodenal tract are epigastric pain, heartburn, and dyspepsia; endoscopy can identify various mucosal characteristics such as hypertrophy, friability, atrophy, and hemorrhagic and erosive lesions. It is important to underline the poor correlations between endoscopic mucosal abnormalities and histological features of the same lesions. In fact, for example, gastric mucosa described endoscopically as normal should show histologically severe signs of inflammation. On the contrary, evident endoscopic damage by drugs (e.g., aspirin) might turn out to be mild phlogistic lesions upon histological examination. We can conclude that the term gastritis should be used in the case of presence of phlogistic characteristics in the histological exam. However, the endoscopic examination has a fundamental role in the clinical scenario of gastritis because the microscopic evaluation is made on the mucosal biopsy. Endoscopic mucosal biopsies concern mucosal abnormalities such as erosion, ulcers, polyps, hemorrhagic lesions, endoluminal protuberances, or in cases of suspicion of *Helicobacter pylori* infection. Furthermore, the identification of *H. pylori* in gastric pathology has given a central role to gastritis. Gastritis includes acute and chronic inflammations of the gastric mucosa. The classifications of gastritis are based on histological data. Unfortunately, also within the histological field, it should be difficult to present a classification of gastritis because there are various criteria that can be followed. First, histological features of inflammation subdivide acute and chronic gastritis. Second, more detailed

*Ali O. Mohamed Bel Khair and Qazi Zeeshan*
