Inflammations of the esophagus comprise acute and chronic types. Acute esophagitis is not common and often duo to infection of bacterium, viruses, fungi or physical and chemical injury. Chronic esophagitis is very common and usually not specific. The pathological gastro-esophageal reflux is a important cause of chronic esophagitis . Refluxed acid leads to cell injury, accelerant desquamation, erosion and ulceration companied by chronic inflammatory cell infiltration, epithelial regeneration and fibrosis. Longstanding reflux results in Barrett’s esophagus recognized as pre-malignant condition in recent years, its feature is that the lower esophagus is lined by columnar epithelia of gastric or intestinal type.
The veins of the lower esophagus are a potential site for porto-systemic shunting of blood with portal hypertension often resulting from cirrhosis of liver. The congested and dilated veins are easily to rupture and cause life-threatening hemorrhage.
Carcinoma of esophagus has the higher incidence related to environmental, hereditary factors and viral infection such as HPV infection. The common site is the middle and lower esophagus. The gross appearance of esophageal carcinoma is divided into following types: medullary, polypoid or fungating, ulcerative and constrictive types. The histological types have squamous carcinoma, adeno-epithelial carcinoma and undifferentiated carcinoma. The squamous carcinoma is the predominant type and graded as well, moderately or poorly differentiated. Esophageal carcinoma can spread to adjacent organs or tissue directly. Lymph nodes metastases and blood stream metastases can occur ,usually depending on the region of the tumor.
Inflammation of the stomach is usually considered as either acute (often described as irritant, hemorrhagic, corrosive or infective types ) or chronic gastritis. The cause of the chronic gastritis is not completely clear, associated factors are H. pylori infection, autoimmune and chemical injury such as reflux of bile. Depending on the pathological characteristic, there are superficial, atrophic, hypertrophic and other types of gastritis. The pathological features of atrophic gastritis are lymphocyte and plasma cell infiltration, glandular atrophy, lamina propria fibrosis and intestinal metaplasia.
Chronic peptic ulcer is arguably the most important gastrointestinal disorder. The major site is first part of duodenum and gastric antrum. Main etiologic factors are hyperacidity, H. pyloric infection, duodenal reflux, non-steroidal anti-inflammatory drugs (NSAIDs), smoking, and genetic factors, resulting in breakdown of mucosal defense. There are marked differences in the pathogenetic mechanisms and genetic background between duodenum and stomach. Chronic peptic ulcer is usually less than 2cm in diameter. The edges are clear- cut and overhang the basis, consisting of exudates, necrotic, granulation tissue and mature fibrous (scar) tissue. The complications of peptic ulcer include hemorrhage, penetration of adjacent organ, perforation, anemia, pyloric obstruction and malignancy.
Appendix is a blind-ended structure lined internally by colonic-type mucosa, surrounded by submucosa and muscle coats. Appendicitis may occur when bacterial infection and obstruction. There are acute and chronic types. The former contains simple, phlegmonous and gangrenous appendicitis, the latter often shows fibrous obliteration.
Chronic inflammatory disease (IBD) embraces Crohn’s disease and ulcerative colitis. The etiology of IBD is unknown. Crohn’s disease frequently involves terminal ileum, but may occur anywhere from mouth to anus, characterized by segmental edema and transmural inflammation with granulomas and fissural ulcers leading to intestinal obstruction and fistulation. Ulcerative colitis often affects colon and rectum, characterized by diffuse superficial inflammation with formation of crypt abscess and ulcer. Acute complication include toxic dilation, perforation, hemorrhage and dehydration; chronic complications are anemia, liver abscess and malignancy.
Gastric carcinoma has a notably high incidence. Associated etiological factors comprise H. pylori infection, environmental, inherited defects in DNA repair and chemical substances. Some conditions such as atrophic gastritis, intestinal metaplasia, partial gastrectomy, polyps, and chronic ulcer have been acknowledged as the precursor to gastric carcinoma. The commonest site is gastric antrum. According to depth of invasion, gastric carcinoma is classified as early or advanced stage. Early gastric carcinoma is confined to either the mucosa or submucosa;advanced gastric carcinoma extend into or beyond the main muscle coats grossly as polypoid (fungating), ulcerative or infiltrating type. Histological types have adenocarcinoma, tubular or papillomatous, with different degree of differentiation, mucoid carcinoma, signet-ring cell carcinoma or undifferentiated carcinoma, etc. Carcinoma can directly spread adjacent organs such as pancreas, transverse colon, liver and spleen depending on the site of tumor. Lymphatic metastases to local or distant lymph nodes can occur. Blood stream metastases to liver are frequently evident at the time of late stage. When involving the serosa, the cancerous cells can fall off leading to peritoneal dissemination and planting. Krukenberg’s tumor of ovaries is a classical example.