3/30/99

Pathology II

 

Esophagitis

·        Injury to esophageal mucosa w/subsequent inflammation

·        In US-10% to 20% of adults (mostly >40yrs)

·        Most cases are due to reflux

·        Heartburn—regurgitation of sour brash

·        Chest pain may mimic a heart attack

·        Barrett's Esophagus

·        Complication of long-standing gastroesophageal reflux

·        Inflammation, eventually w/ulceration

·        Normal squamous replaced by metaplastic columnar epithelium

·        30-40 fold increase in risk of adenocarinoma

·        2° complications include local ulceration bleeding  and stricture

·        Esophageal Carcinoma

·        Adults over 50 w/ 3:1 male ratio

·        3-4 fold higher incidence in blacks

·        US:  incidences 6 in 100,000 1-2% of cancer deaths

·        China incidence 100/100,000—20% of cancer deaths

·        Barrett's esophagus is only recognized precursor of esophageal adenocarinoma

·        Risk factors for squamous cell carcinoma

·        Esophageal Disorders

·        Long-standing esophagitis

·        Tobacco

·        Alcohol consumption

·        Dietary

·        Deficiency of vitamins A, C, riboflavin, thiamine, pyridoxine

·        Deficiency of trace metals (zinc, molybdenum)

·        Fungal contamination of foodstuffs

·        High content of nitrites/nitrosamines

·        Genetic Predisposition

·        Tylosis (hyperkeratosis of palms and soles)

·        Clinical

·        Insidious onset

·        Weight loss, anorexia

 

Gastritis

·        The presence of chronic mucosal inflammatory changes leading eventually to mucosal atrophy and epithelial metaplasia

·        Most important etiologic association is chronic infection w/Helicobacter pylori

·        Worldwide—80% of Puerto Rican adults are infected

·        50% of American adults over the age of 50

·        mechanism of damage uncertain—probably combined influence of bacterial enzymes and toxins and release of chemicals from recruited neutrophils

·        Tx w/ab result in improvement

·        autoimmune gastritis

·        mostly asymptomatic

·        upper abdominal discomfort, nausea and vomiting

·        increased risk

·        acute chronic—acute transient mucosal inflammation

·        sloughing of superficial mucosa (erosion) may cause bleeding

·        major cause of hematemesis in alcoholics

·        also NSAIDs (aspirin), heavy smoking, cancer chemotherapy drugs, systemic infections, severe stress (burns, trauma, surgery), suicide attempts w/acids/alkali

 

Gastric Ulcers

·        ulcers are a breach in the mucosa that extends through the muscularis mucosa into the submucosa or deeper

·        erosions are superficial, ulcers are deep and require more time to heal

·        stomach and duodenum

Peptic Ulcers

·        chronic, usually solitary—remitting, relapsing lesions

·        98% in proximal duodenum or stomach (4:1)

·        pathogenesis

1. mucosal exposure to gastric acid and pepsin

·        interference w/host mechanisms to digestion of gastric mucosa

2. H. pylori infection

·        Almost 100% of duodenal ulcers an 70% of gastric ulcers are infected

·        Only 10% to 20% infected worldwide develop ulcers

·        Pathology

·        Sharply punched-out craters 2-4 cm in diameter

·        Margins are perpendicular, not elevated or beaded

·        Clinical

·        Epigastric gnawing, burning, or boring pain

·        Worse at night and occurs 1-3 hrs after meals

·        Relived by alkalis or food

·        Bleeding is chief complication

·        W/o Tx, healing on the average takes 15 yrs

 

Gastric Carcinoma

·        3% of all cancer deaths in US

·        very poor prognosis: <10% 5yr survival rate

·        higher incidence in Japan, Colombia, Costa Rica, Hungry

·        intestinal variant—arises from metaplastic changes due to chronic gastritis

·        this pattern is progressively decreasing in frequency in US

·        Diffuse variant—arise de novo from gastric cells, not associated w/chronic gastritis

·        This pattern has not changed in frequency and constitutes ½ of gastric carcincoma

·        Lesser curvature of stomach of antropyloric region

·        3 growth patterns

1. exphytic—protrusion of mass into lumen
2. flat or depressed—no mass, stays w/in wall
3. excavated—erosive crater

·        Linitis plastica—leather bottle stomach—uncommon large region or entire stomach is extensively infiltrated by malignancy.  Stomach is rigid and thickened

·        asymptomatic until late stages—then abdominal discomfort or weight loss

·        only hope is early Dx and surgical removal

·        discovered by repeated endoscopic

 

Hirschsprung:  Congenital Megacolon

·        distention of colon to >6-7 cm in diameter

·        Occurs in 1 in 5000 to 8000 births; males predominate 4:1

·        More frequent in those w/other congenital anomalies such as hydrocephalus ventricular septal defect, and Meckel's diverticulum