Gastrointestinal Pathology Flashcards
Serosa
Outer layer of GI tract
Epithelium of peritoneum and connective tissue
Muscularis
Second to outermost layer of GI tract
Outer longitudinal layer, inner circular layer, myenteric plexus
Submucosa
Second from inner layer
Submucosal plexus, glands, blood vessels
Mucosa
Innermost layer
Smooth muscle, loose connective tissue, epithelium
Main functions of GI system
Ingestion, mastication, deglutition, digestion, absorption, excretion
Cleft lip
Congenital abnormality
Clefting of the lip, and sometimes palate
Due to failed fusion of nasal and maxillary processes in fetal development
Common to certain families
Repaired by modern orthodontic surgery
Dental caries
One of the msot common human diseases
Due to accumulation of bacterial plaques that erode through dentin and penetrate into the tooth
Prevented through water fluorination, brushing and dental hygiene
Stomatitis
Inflammation of the mouth
Causes of stomatitis (2)
- Herpes virus infection
2. Candida albicans infection (thrush)
Aphthous stomatitis
Canker sores
Painful, recurrent, spontaneous healing oral ulcers of unknown etiology
Oral cancers
Usually squamous cell carcinoma
Often related to alcohol and tobacco smoking
Some related to HPV
Morphology of oral cancer
Leukoplakia
Erythroplakia
Ulcer
Nodule
Leukoplakia
White plaque
Erythroplakia
Red plaque
Esophageal clinical presentations (5)
- Dysphagia
- Odynophagia
- Retrosternal burning
- Aspiration
- Regurgitation
Dysphagia
Difficulty swallowing
Odynophagia
Retrosternal chest pain during swallowing
Hiatal hernia
Sliding or paraesophageal
Proximal part of stomach herniates into thoracic cavity
Acquired condition
Paraesophageal hiatal hernia
Uncommon
Can be life threatening
Can become ischemic, and if it becomes necrotic a sugery is needed
Sliding hiatal hernia
Very common not usually clinically significant
Esophageal varices
Dilated veins in the distal esophagus
Usually due to portal hypertension in patients with cirrhosis of the liver
Rupture can result in catastrophic upper GI bleeding
Esophagitis
Inflammation of the esophagus, common causing heartburn
Causes of esophagitis (3)
- Reflux esophagitis
- Infectious esophagitis
- Chemical irritants
Reflux esophagitis
GERD
Due to reflux juices into esophagus
Infectious esophagitis
Viruses (HSV), fungi (Candida)
typically in immunosuppressed persons
Chemical irritants
Exogenous chemicals (lye) Pill (medications, getting stuck)
Carcinoma of the esophagus
4% of cancers Higher incidence in Asia and Africa Poor prognosis Squamous cell carcinoma (upper or lower) Adenocarcinoma in lower develops in Barrett's esophagus (intestinal metaplasia)
Barrett’s esophagus
Biggest risk factor for cancer
Due to reflux
Adenocarcinoma, can metastasize throughout intestines
Stomach clinical presentations (5)
- Pain
- Vomiting
- Bleeding
- Dyspepsia
- Systemic consequences (B12 deficiency, anemia)
Hematemesis
Vomiting blood
Melena
Black tarry stool
Dyspepsia
Abdominal discomfort
Gastritis
Acute or chronic
Acute gastritis
Erosive
Stress, shock, food, exogenous chemicals, drugs
Ulcerations
Chronic gastritis
Helicobacter pylori related
Autoimmune (with pernicious anemia)
Peptic ulcers
Can bleed
Multifactorial
Mucosa is broken and replaced by granulation tissue
Can erode into an artery and cause significant hemorrhage
Peptic ulcers contributing factors (3)
- Gastric acid
- Mucosal barrier defects (stress, shock, NSAIDs, smoking)
- Helicobactor pylori infection
Peptic ulcer complications (4)
- Hemorrhage
- Penetration into the pancreas
- Perforation (peritonitis)
- Cicatrization
Cicatrization
Scarring, stenosis
Gastric tumors
Benign or malignant
Benign gastric tumors
Polyps
Malignant gastric tumors
Adenocarcinoma, lymphoma
Carcinomas of the stomach
Adenocarcinoma
More common in Japan and Chile
Etiology is not clear - nitrosamines in food, H pylori
Superficial, polypoid, ulcerated, diffuse infiltrating
Linitis plastica
Carcinoma of the stomach
Diffuse infiltrating
Stomach becomes very hard, like leather
Intestines clinical presentations (5)
- Diarrhea
- Blood in stool
- Abdominal pain
- Obstruction
- Weight loss
Gastrointestinal infections
Often cause acute, self-limited diarrheal illness (excluding Giardia)
Causes of infectious diarrhea (4)
- Viral infections
- Bacterial infections
- Bacterial toxins
- Parasites
Viral infections causing diarrhea
Rotavirus, Norwalk virus
Bacterial infections causing diarrhea
E coli, Campylobacter jujuni, Clastridium difficile
Travels diarrhea
Bacterial toxins causing diarrhea
Shigella toxin
Food poisoning
Usually the same day
Parasites causing diarrhea
Giardia lamblia
Malabsorptive syndromes
Inability of intestine to absorb nutrients from food
Most common in Canada is Celiac sprue
Celiac sprue
Hypersensitivity to gliaden (break down of gluten)
Injury to duodenal villi causes them to be flattened
Weight loss, diarrhea, nutritional deficiencies
Inflammatory bowel disease
Chronic inflammation disease of the intestines
Causes chronic abdominal pain and diarrhea (blood, mucus)
Crohns and Ulcerative Colitis
Might be familial
Crohns Disease
Segmental distribution, including small intestine
Thickening of wall with stricture of the intestine
Deep, transmural ulcers, inflammation
Granuloma, fistula, cancer
Cobblestone inflammation
Ulcerative Colitis
Continuous involvement of the colon
Limited to mucosa, but can have superficial ulcers and inflammatory pseudopolyps
Never involves ileum, small intestine and is never patchy
Causes of intestinal obstruction (2)
- Paralytic ileus
2. Mechanical (obstructive) ileus
Mechanical ileus (7)
- Atresia or stenosis
- Stricture
- Intussusception
- Volvulus
- Hernia
- Adhesions
- Neoplasms
Intussusception
Invagination of one segment of the intestine into the following segment
Volvulus
Twisting of the intestine around its mesenteric root, which cuts off blood supply
Hernia
Protrusion of the abdominal contents into the abdominal wall
Usually due to weakness or defect in abdominal wall
Bowel can close off and become necrotic
Asymptomatic except bulge
Diverticulosis of the colon
Outpouchings of the colon
Congenital or acquired due to increased intraluminal pressure in sigmoid
Very common in Canada
Complications of diverticulosis of the colon
Inflammation, strictures, fistulas, rupture causing peritonitis
Hemorrhoids
Dilated submucosal veins in anal canal
Bleeding, pain
Angiodysplasia
Abnormal submucosal vessels that can bleed in the colon
Ischemic bowel disease (3)
- Acute thrombosis of mesenteric arteries, veins (mesenteric thrombosis)
- Vasculitis
- Mechanical obstruction of vessels
Mesenteric thrombosis
Ischemic bowel disease
Can be due to atherosclerosis
Infarction of intestines, can be fatal
Intestinal neoplasms
Colon mostly
Epithelial tumors (adenomas/carcinomas) are 90%
More common than lymphomas or mesenchymal tumors
Classification of intestinal tumors (3)
- Non-neoplastic polyps
- Benign neoplasms
- Malignant neoplasms
Non-neoplastic polyps of the intestine
Hyperplastic polyp, inflammatory polyp, juvenile polyp, Peutz-Jeghers polyp
Benign neoplasms of the intestine
Tubular ademona, villous adenoma, tubulovillous adenoma, benign stromal tumors
Malignant neoplasms of the intestine
Adenocarcinoma, carcinoid, lymphona, sarcoma
Carcinoma of the large intestine
Third most common cancer of the interal organs
Genetic factors - Colon Cancer (2)
- Familial adenomatous polyposis
2. Hereditary non-polyposis colorectal cancer (Lynch syndrome)
