Gastrointestinal Flashcards
Oral Leukoplakia
- ETIOLOGY: well-defined white patch or plaque
- Older males
- Precancerous until proven otherwise
- 3-7% undergo malignant transformation
• PATHOGENESIS: caused by epidermal thickening or hyperkeratosis
RISK FACTORS:
• Tobacco (pipe-smoking or chewing)
• Chronic friction: ill-fitting dentures
• HPV infection
SYMPTOMS: not removed with scraping
Erythroplakia
- ETIOLOGY: less common than leukoplakia but more severe
- Malignant transformation in >50% → squamous cell carcinoma
PATHOGENESIS: marked dysplasia
- Pre-disposing factors: Alcohol and Tabacco
SYMPTOMS: red velvety eroded area
- red plaque → Red Flag → Presence of Vascularization
Oral Hairy Leukoplakia
- ETIOLOGY: seen in HIV patients
- No malignant potential
- Most common in older men and tobacco use
HISTOLOGY
- Hyperkeratosis - Epidermal thickening of the Stratum Conreum with acanthosis ( thickening of the lower layers)
- Increased number of inoculated layers of keratin
- Thick toungue due to keratin
• PATHOGENESIS: EBV
• MORPHOLOGY: layers of keratotic squames on underlying mucosal
acanthosis (hyperkeratotic)
• Fluffy and raised
Oral Squamous Cell Carcinoma
- AT RISK: chewing tobacco, alcohol, jagged teeth, HPV 16/18
- PATHOGENESIS: loss of p53
- MORPHOLOGY: white/yellow/red sore
- SYMPTOMS: asymptomatic
- Most common: (1) vermillion border of lip (2) floor of mouth (3) lateral tongue
- Metastasis to anterior cervical lymph nodes
• DIAGNOSIS: biopsy → keratin pearls
Esophageal Atresia
• PATHOGENESIS: disruption of elongation and separation of esophagus and trachea during embryogenesis
- SYMPTOMS: excessive drooling in newborn
- Choking and cyanosis with first feed
- Tracheo-esophageal fistula
- Maternal polyhydramnios - aminotic fluid not swallowed by fetus = abdmonial distention → air in the stomach
Plummer-Vinson Syndrome Kelly Patterson Syndrome
• ETIOLOGY: genetic → females > males
- seein in post-menopausal women who have blleding
• Web = 2 layers, Ring = 3 layers
- concentric rings or normal esophageal tissue
- food impaction
- stricture
- perforation
• PATHOGENESIS: dysphagia due to esophageal webs ( protrusion of mucosa + obstruction of the lumen) , glossitis( beefy red tounge) , and
hyprchromic iron deficiency anemia
- SYMPTOMS:
- Koilonychia (spoon-shaped nails)
- Splenomegaly- due to iron deficiency
- Hypochromic anemia
- COMPLICATIONS: can progress to squamous cell carcinoma
- TREATMENT: iron supplementation, endoscopic dilation
Hiatal Hernia
- ETIOLOGY: herniation of stomach through enlarged diaphragmatic hiatus
- Sliding type (95%) → stomach herniates into esophagus → reflux
- Paraesophageal (rolling) type (5%) → stomach herniates beside esophagus
• PATHOGENESIS: incompetence of LES (sliding type)
- SYMPTOMS:
- Sliding Type: reflux of gastric contents, epigastric pain, heart burn
- Rolling Type: volvulus, strangulation, perforation
- bowel sounds are heard in the lower left lung field
- fundus herniates up due to defect in diaphragm
Achalasia / Cardiospasm
• Functional esophageal obstruction
• Three main features
– Partial or incomplete relaxation of LES with swallowing
– Aperistalsis
– Increased resting tone of LES
• ETIOLOGY: incomplete relaxation of LES
- PATHOGENESIS:
- Primary: loss of ganglion cells in myenteric plexus and Loss of intrinsic inhibitory innervation of LES
- Secondary: Chagas Disease, Polio, Paraneoplastic syndromes, Sarcoidosis, diabetic autonomic neuropathy
- SYMPTOMS:
- Dysphagia
- Odynophagia
- Vomiting
- Aspiration Pneumonia
- Progressive dilation of esophagus above LES (bird’s beak appearance)
- Squamous cell carcinoma (5%)
Mallory-Weiss Syndrome
• Longitudinal mucosal/mural tear at the esophageal function
ETIOLOGY: frequently in alcoholics after bout of severe retching
(vomiting)
• PATHOGENESIS: inadequate relaxation of LES during vomiting
- increase pressure from the abdomen + vasospasms of the esophagus
- SYMPTOMS: mucosal tears at EG junction
- alcohol → severe retching → Painful hematemesis
- Usually heals but may be fatal
- melena
COMPLICATIONS
- BoerHaave Syndrome → Transmural rupture of esophagus → Severe chronic vomiting or retching
- Air exists mediastinum
- Air under skin in the neck → Subcutaneous emphysema
Esophagitis
- inflammation of Squamous Mucosa
- IRRITANTS: alcohol, acids, alkalis → reflux esophagitis → GERD
- INFECTIONS: HSV, CMV, Candidiasis → yeast + pseudohyphae
- ALLERGIC: eosinophilic esophagitis
- UREMIA
- ANTICANCER THERAPY
Eosinophilic Esophagitis
→ Allergic reaction to a unknown antigen → immune mediated
- MORPHOLOGY: elongation of lamina propria papillae
- Hyperemia
- Trachealization of the esophagus (rings + white plaques)
- Eosinophils, neutrophils
- Basal Zone hyperplasia
PRESENTATION
- Children → feeding intolerance & GERD symptoms
- Adults → Food impaction & dyphagia
INVESTIGATIONS
- endoscopy
CLASSIC
- Dysphagia
- Poor response to GERD treatment
- Eosinophils on biopsy
Reflux Esophagitis
- ETIOLOGY:
- CNS depressants
- Hypothyroidism
- Alcohol
- Nasogastric intubation
- Tabacco
- Pregnancy
- Obesity
- SYMPTOMS:
- Dyspepsia
- Burning
- Water-brash
- Exacerbation upon lying down
- Nocturnal cough
- PATHOGENESIS:
- Decreased LES tone
- Delayed esophageal clearance
- Decreased reparative capacity of esophagus
• Increased gastric volume
- COMPLICATIONS:
- Bleeding
- Aspiration pneumonia
- Barrett Esophogus
- Adenocarcinoma
Barrett Esophagus
• ETIOLOGY: replacement of esophageal squamous mucosa with
metaplastic columnar epithelium with goblet cells
• Long standing esophageal reflux (GERD)
- Men > women
- White people
• PATHOGENESIS: proliferation of stem cells in lower 1/3 of
esophagus which differentiate into columnar cells (more resistant to acid injury)
• MORPHOLOGY: salmon pink patches above EG junction
- SYMPTOMS:
- Heart burn - worst when lying down
- Dyspepsia
- Epigastric pain
- Substernal discomfort
- Relived with antacids
- 30-40x increased risk for adenocarcinoma
- Waterbrash - metallic taste of acid in the mouth
• DIAGNOSIS: serial endoscopic biopsies
Esophageal Varices
- ETIOLOGY: dilated, tortuous vessels in mucosa and submucosa of lower esophagus
- Alcoholics
- portal hypertension → back up into liver
- the distal esophageal vein drains into portal vein via left gastic vein
- left gastic vein backs up into esophageal vein causing dilation
- dilated tortuous collaterals in the lower esophagus + proximal stomach
- PATHOGENESIS: portal hypertension due to liver cirrhosis
- increased association with decompensated cirrohsis and hepatocellular carcinoma
- SYMPTOMS: usually asymptomatic until rupture
- Non-painful hematemesis
• Cause of death in 50% of patients with
advanced cirrhosis
Esophageal Squamous Cell Carcinoma
- ETIOLOGY: adults >50 years old
- Black people
- Males > females
- Central Asia, Northern China
•Vitamin deficiency, Thiamine
- LOCATION:
- 20% upper 1/3 of esophagus
- 50% middle 1/3 of esophagus
- 30% lower 1/3 of esophagus
- PATHOGENESIS:
- Long standing esophagitis
- Achalasia
- Plummer-Vinson Syndrome
Celiac disease
Ectogermal dysplasia - begins as in-situ lesion in the form of squamous dysplasia
- MORPHOLOGY:
- Exophytic
- Diffusely infiltrative
- Ulcerated / excavated
- DIAGNOSIS: barium swallow - obstruction of lumen
- HISTOLOGY → Keratin Pearls
- METASTASIS: adjacent mediastinal structures (trachea, heart)
Adenocarcinoma
Gland forming tumor - infiltrates basement membrane
- ETIOLOGY: precursor lesion = Barrett esophagus + GERD
- Lower 1/3 of esophagus
- 50 years old
- White males
- PATHOGENESIS: multistep process through dysplasia
- Reflex esophagitis → Barrett Esophagus → Dysplasia → Adenocarcinoma
- COMPLICATIONS
- Melena →DIC
- Tracheoesophageal fistula →Aspriation pnemonia→ Lung Abscesses
- invades heart→ Pericarditis→ Pericardial Effusion
Pyloric Stenosis
• ETIOLOGY:
- M:F→ 3:1
- Congenital: more common in first male child→ associated with Tuner Syndrome, Trisomy 18, and Esophageal Atresia
- Acquired: chronic antral gastritis, peptic ulcers, malignancy
- PATHOGENESIS: concentric hypertrophy of circular muscle coat • SYMPTOMS:
- Regurgitation
- Projectile vomiting→ Non billious
- Palpable epigastric mass→ Olive-like
- Visible peristalsis • TREATMENT: myotomy
Acute Gastritis
- ETIOLOGY: acute erosive gastritis
- NSAIDs
- Alcohol
- Ischemia / shock
- Severe stress (burns, surgery)
- PATHOGENESIS: loss of surface epithelium due to erosions
- Full thickness mucosal injury: ulcer
- Erosions and hemorrhage seen on endoscopy
- Acute mucosal process of transient nature
- Inflammation associated with hemorrhage and in severe cases erosion lading to GI bleed
- MORPHOLOGY: hyperemia, punctate areas of hemorrhage
- Edema / congestion of lamina propria
- Neutrophils in surface epithelium (secondary to epithelial necrosis)
- Transmural = Erodes all layers
Chronic Gastritis
- ETIOLOGY: chronic mucosal inflammation
- Chronic H.pylori infection
- Autoimmune
- Alcohol + smoking
• MORPHOLOGY: mucosal atrophy and metaplasia
- SYMPTOMS: asymptomatic
- Nausea
- Vomiting
- Epigastric discomfort
- Dyspepsia (acid reflux)
- Indigestion
H.Pylori Gastritis
- PATHOGENESIS: urease and phospholipase
- Pain is relieved after you eat
- Never becomes malignant
- MALToma
- Antro-pyloric region of lesser curvature
• MORPHOLOGY:
• Lymphocytes and plasma cells in lamina propria
• PMNs in surface epithelium (indicates currently
active inflammation)
• Reactive lymphoid aggregates - chronic inflammatory infiltrates
- DIAGNOSIS:
- Invasive: rapid urease test, biopsy, PCR
- Non-invasive: urea breath test( NH3 + CO2 → which is measured), serology, PCR
Autoimmune Gastritis
- ETIOLOGY: anti-parietal cell or anti-intrinsic factor antibodies
- Mainly involves body and fundus
• PATHOGENESIS: gland oxyntic destruction → atrophy → loss of acid
production + loss of IF (oxyntic cells)→ Vit B12 deficiency
- Chronic inflammation
- Gastric atrophy
- Intestinal metaplasia
- SYMPTOMS
- Achlorhydria (low HCl)
- Pernicious anemia
- Increased gastrin levels
- No relief with antacids
- Long term risk of gastric carcinoma
- Risk factor for carcinoid tumors
Acute Gastric Ulcers
• ETIOLOGY: severe trauma, major surgeries, extensive burns (curling
ulcers), head injuries (cushing ulcers)
- PATHOGENESIS:
- Systemic acidosis and hypoxia
• Vagal stimulation (intracranial lesions)
- SYMPTOMS: Usually multiple small circular ulcers, but asymptomatic
- Normal gastric ruggae
• May present with upper GI bleed
Peptic Ulcer Disease
- ETIOLOGY:
- H.pylori
- NSAIDs: inhibit PGE synthesis
- Smoking: impairs mucosal blood flow
- Alcohol
- Psychological Stress
- Zollinger-Ellison syndrome (multiple ulcers)
Gastronemia→ îgastrin→ îacid = ulcers
- LOCATION: (1) duodenum, (2) stomach, (3) GE junction
- MORPHOLOGY: round / oval, punched out with ”spoke-like ruggae”
- 4 main zones:
- 1) Necrotic fibrinoid debris
- 2) Non-specific inflammatory infiltrate (PMNs)
- 3) Granulation tissue
- 4) Fibrosis + collagenous scar
- SYMPTOMS:
- Burning epigastric pain 1-3 hours after meals
- Relieved by food and alkali - due to CCK + Bicard reaction in lumen
- Worse at night (no food at night to help buffer acid)
- Associated weight loss
- Complications: bleeding, perforation, malignant transformation
Reactive Gastropathy
• ETIOLOGY: patients with painful, chronic inflammatory conditions
• PATHOGENESIS: chronic NSAID use → inhibition of PGE/COX → weak
gastric mucosa →
Gastric Adenocarcinoma
- ETIOLOGY: highest occurrence in Japan and South Korea
- Pylorus/Antrum: 50-60%
- TYPES:
- Intestinal: chronic gastritis due to H.pylori → metaplasia is precursor
- Older patients
- Sister Mary Joseph nodule
- Diffuse: E-cadherin mutation → no gland formation or metaplasia
- Young females
- Signet ring cells
- Leather-bag appearance (linitis plastic appearance)
- GROWTH PATTERNS:
- Exophytic
- Flat
- Endophytic (Excavated)
• SYMPTOMS:
• Early Carcinoma: confined to mucosa and submucosa
• Advanced Carcinoma: Krukenberg tumor, Virchow’s lymph node (left
supraclavicular lymph node)
GI Stromal Tumors (GIST)
- ETIOLOGY: previously misdiagnosed as leiomyomata
- Submucosal
- PATHOGENESIS: Cells of Cajal (pacemaker cells of enteric plexus)
- CD117 tumor marker
• c-Kit mutation in exon 11
- MORPHOLOGY: whorls and bundles of spindle shaped cells
- Kit mutations (Imatinib = Kit inhibitor)
Meckel’s Diverticulum
- ETIOLOGY: Rule of 2’s
- 2% of normal population
- First 2 years of life
- 2 feet from ileo-cecal valve
- 2 inches long
- 2 types of tissue: gastric + pancreatic
- PATHOGENESIS: incomplete involution of the vitelline duct
- True diverticulum: includes all layers of the GIT
• LOCATION: anti-mesenteric border
- SYMPTOMS: asymptomatic
- Painless rectal bleeding
- Meckel’s Diverticulitis (mimic’s appendicitis)
- Perforation
- Fistula
- Peptic ulver
- Hemorrhage
Celiac Sprue
- ETIOLOGY: common in whites, 1-10 years old
- HLA DQ2/DQ8
- PATHOGENESIS: atrophy and loss of villi (reduced SA)
- Proximal part of intestine
- MORPHOLOGY:
- Increased intraepithelial lymphocytes
– Typical: Villous atrophy
• Elongated and hyperplastic crypts (for compensation)
• Increased immune cells in lamina propria
- SYMPTOMS: chronic diarrhea (w/ steatorrhea)
- Iron deficiency anemia
- Long-term risk of T-cell lymphomas
- DIAGNOSIS:
- Anti-gliadin / Anti-endomysial antibodies
- Anti-tissue transglutaminase (tTG) antibodies
• TREATMENT: reversal of epithelium changes after gluten-free diet
Tropical Sprue
• ETIOLOGY: people living or visiting tropical areas → contract diarrheal illness
• PATHOGENESIS: bacterial infection superimposed on pre-existing
small intestine injury
• Diffuse throughout intestine
- Damage to brush border→ failure of reabsoprtion of micelles
- secondary folate + Vit B12 deficiency
- SYMPTOMS: appear months or years after visit
- TREAMENT: responds to antibiotics + Supplemental Folate
Whipple Disease
- ETIOLOGY: systemic → intestines, joints, CNS
- Males > females
- PATHOGENESIS: gram positive actinomycete → Tropheryma whippelii
- Macrophages try to digest bacteria
- Accumulation of macrophages causes congestion in lamina propria
- Compression of lacteals (→ abnormal fat absorption)
- MORPHOLOGY: distended macrophages in lamina propria
- Possible granulomatous inflammation
- SYMPTOMS: malabsorption and steatorrhea
- DIAGNOSIS: PAS–positive granules containing bacteria
- Mucosa laden with distended macrophages in lamina propria-contain PAS positive granules
- TREATMENT: responds to antibiotics
Giardia
• Protozoan gut pathogen with flagellum
– Trophozoites and cysts are shed
• Usually acquired from drinking water contaminated with cysts
– Poor sanitation and crowded living conditions predispose to infection
• Immunosuppression increases risk
Cryptosporidium
- Self-limited infection in a normal host
- Chronic diarrhea in AIDS
- Intracellular but appears at top of cell microscopically
Luminal Obstruction
- Food bolus: macaroni, sauerkraut, fruit or vegetable
- Therapeutic agents: barium sulfate, antacid gels
- Bezoars: ingested hair
- Parasite: Ascaris lumbricoides (round worms)
- Tumors
- Swallowed foreign bodies: dentures, bones, pins, coins, screws, nails
- Endogenous origin:
- Meconium ileus in infants (Cystic Fibrosis)
- Gallstone ileus: stone >2.5cm
Intramural Obstruction
→
• Congenital atresias
- Inflammatory conditions:
- Crohn’s Disease
- Tuberculosis - causes transmural granulomatous inflammation of intestine with makred congestion, edema + fibrinoud adhesions → eventually replaced with scar tissue
- Drug-induced stenosis
- Ischemic strictures
- Radiation damage
- Polypoid neoplasms
Extramural Obstruction
•Mechanical→ involement of entire segment
- Diseases of peritoneum:
- Congenital mesenteric/omental bands
- Peritoneal tumors
- Peritoneal adhesions - bands of adhesion tissue→ fibrinious bridges within which bowels are trapped
- Hernias
- Intussusception: telescoping of proximal bowel segment into distal
- Often in adults due to tumor
lymphoid hyperplasia in children→ strong association with adenovirus infections
• Volvulus: twisting of bowel loop