Gastrointestinal pathology Flashcards
1
Q
Herpes labialis
A
- Common vesicular lesion caused by herpes simplex virus (HSV)
- Most often caused by HSV-1
- Tends to recur, with activation by febrile illness, trauma, sunshine, or menstruation
2
Q
Aphthous stomatitis
A
- Characterized by painful, recurrent, erosive oral ulcerations
3
Q
Oral candidiasis
A
- Local, white membranous lesion caused by Candida albicans
- Occur most commonly in debilitated infants and children, immunocompromised patients, and individuals with diabetes
4
Q
Papilloma (oral mucosa)
A
- Most common benign epithelial tumor of the oral mucosa
- Can occur anywhere in the mouth, but most common sites are tongue, lips, gingival, or buccal mucosa
5
Q
Fibroma (oral mucosa)
A
- Most often a non-neoplastic hyper plastic lesion resulting from chronic irritation
6
Q
Leukoplakia
A
- Clinical term describing irregular white mucosal patches
- Results from hyperkeratosis, usually secondary to chronic irritation
- Usually benign, but may represent dysplasia or carcinoma in situ
7
Q
Oral cancer
A
- Most frequently squamous cell carcinoma
- Involvement of tongue occurs in more than 50% of cases
- Tobacco and alcohol are major risk factors
8
Q
Sialadenitis
A
- Inflammation of the salivary glands
- May be caused by infection, immune mediated mechanism, or the most common cause: occlusion of the salivary ducts by stones (sialolithiasis)
9
Q
Ranula
A
- Large mucocele of salivary gland origin
- Characteristically localized to the floor of the mouth
10
Q
Pleomorphic adenoma (salivary gland)
A
- Mixed benign tumor - presence of myxoid and cartilage-like elements, as well as epithelial cells
- Most frequently occurring salivary gland tumor
- Usually arises in parotid gland (90%)
- Rarely may transform into carcinoma - presents with signs of facial nerve damage
11
Q
Warthin tumor
A
- Benign cystic tumor with abundant lymphocyte and germinal centers
- 2nd most common tumor of salivary gland
- Almost always arises in parotid
- Comprised of admixed epithelial and lymphoid elements
- “Motor oil” quality in cyst fluid
12
Q
Tracheoesophageal fistula
A
- Congenital defect resulting in connection between esophagus and trachea
- Most common variant (90%) - lower portions of esophagus communicates with the trachea near the tracheal bifurcation
- Second most common variant - fistulous connection between the upper esophagus and the trachea
- Third variant - fistulous connection between the trachea and a completely patent esophagus
13
Q
Esophageal diverticula
A
- Pouches lined by one or more layers of the esophageal wall
- False (pulsion) diverticula - most common, result from herniation of the mucosa through defects in the muscular layer
- True (traction) diverticula - less common, consist of mucosal, muscular, and serial layers. Result from periesophageal inflammation and scarring
- Locations:
(1) Zenker diverticulum - most common (70%), immediately above the upper esophageal sphincter
(2) Near the midpoint of the esophagus
(3) Epiphrenic diverticulum - Immediately above the lower esophageal sphincter
14
Q
Achalasia
A
- Presistent contraction of the lower esophageal sphincter and absence of esophageal peristalsis, leading to a dilation of the esophagus
- Due to damaged ganglion cells in myenteric plexus - one important source is Trypanosoma cruzi infection in Chagas disease
- Most cases (primary) - idiopathic
- “Bird-Beak” sign on barium swallow
- Squamous cell carcinoma in 5% of subjects
15
Q
Esophageal varices
A
- Dilated submucosal esophageal veins
- Occur secondary to portal HTN
- Present in 90% of cirrhotic patients, usually due to alcoholism
- Can result in upper GI hemorrhage
- 40% die in first episode of bleeding varicose; rebreeding occurs in 50% of survivors within 1 year
16
Q
Gastroesophageal reflux (GERD)
A
- Reflux of gastric acid contents into the esophagus
- Most commonly, associated with hiatal hernia and incompetent LES tone
- Also associated with excessive use of alcohol and tobacco, and increased gastric volume, pregnancy, or scleroderma
- Clinical: heartburn, asthma and cough, damage to enamel of teeth
- May cause esophagitis, structure, ulceration, or Barrett esophagus
17
Q
Barrett esophagus
A
- Columnar metaplasia of esophageal squamous epithelium
- The columnar epithelium is often of the intestinal type with prominent goblet cells - “salmon pink” appearance
- Complication of long-standing GERD and is a well-known precursor of dysplasia and, ultimately, esophageal adenocarcinoma
- Almost always associated with sliding hiatal hernia
18
Q
Candida esophagitis
A
- White adherent mucosal patches and painful, difficult swallowing
- Associated with antibiotic use, DM, malignant disease, or immunodeficiency caused by AIDS
- Most common cause - GE relfux
19
Q
Esophageal carcinoma
A
- Manifested clinically by dysphagia, wight loss, and anorexia. Pain and hematemesis may occur
- Shift from squamous cell carcinoma to adenocarcinomas in US, France, and elsewhere
(1) Squamous cell carcinoma - most common esophageal carcinoma worldwide. Arises most frequently in the upper and middle thirds of the esophagus. Overexpression of cyclin D1, cyclin E and EGFR; inactivation of o53, Rb, and p16
(2) Adenocarcinoma - most common esophageal carcinoma in US. Arises most frequently in the lower third of the esophagus from preexisting Barrett esophagus - Metastases usually to liver, lungs, pleura
20
Q
Congenital pyloric stenosis
A
- Congenital hypertrophy of pyloric smooth muscle
- More common in boys
- Classically present two weeks after birth: projectile non bilious vomiting, visible peristalsis, olive-like mass in abdomen
21
Q
Acute gastritis
A
- Acidic damage to mucosa, with acute inflammation, necrosis, and hemorrhage
- Due to imbalance between defenses and acidic environment
- Causes: NSAIDs, cigarette smoking, heavy alcohol intake, Curling ulcer, Cushing ulcer
22
Q
Chronic gastritis
A
- Chronic mucosal inflammation and atrophy of the mucosal glands
(1) Autoimmune gastritis: - Autoimmune destruction of gastric parietal cells
- Associated with antibodies against parietal cells and/or intrinsic factor
- Type IV hypersensitivity reaction
- Increased risk for gastric adenocarcinoma
(2) Helicobacter pylori gastritis: - Most common form of chronic gastritis
- Often, increased gastric acid secretion occurs
- H. Pylori ureases and pot eases and inflammtion weaken mucosal defenses
23
Q
Peptic ulcer of the stomach
A
- Acocunt for 10% of peptic ulcer disease
- Usually due to H. pylori (70%); other causes include NSAIDs and bile reflux
- Presents with epigastric pain that worsens with meals
- Ulcer usually located on lesser curvature of antrum; rupture carries risk of bleeding from left gastric artery
24
Q
Gastric carcinoma
A
- Malignant proliferation of surface epithelial cells (almost always adenocarcinoma)
- Increased incidence in men. Occurs more frequently in persons with blood group A
(1) Intestinal type: - Presents as large, irregular ulcer with heaped up margins
- Most commonly involves lesser curvature of antrum
- Risk factors; intestinal metaplasia, nitrosamines in smooked foods, and blood type A
(2) Diffuse type: - Signet ring cells that diffusely infiltrate gastric wall
- Desmoplasia results in thickening of stomach * Not associated with H. pylori, intestinal metaplasia, or nitrosamines
25
Gastrointestinal stromal tumors (GISTs)
- Mesenchymal tumors derived from the pacemaker cells of Cajal
- Most common in the submucosa of the stomach but can also occur in the small intestine, large intestine, and extragastrointestinal sites
- Tumor cells express the c-kit oncogene (CD117); also GIST are positive for CD34 approx. 60-60% of the time
- Three main categories; Spindle cell type (70-80%), epithelia type (20%), mixed type (<10%)
26
Peptic ulcer of small intestine
- Always associated with hypersecretion of gastric acid and pepsin
- Almost always due to H. pylori
- Sometimes associated with intake of spiring or other NSAIDs, smoking, Zollinger-Ellison syndrome, primary hyperparathyroidism, multiple endocrine neoplasia (MEN) type I
- Present with epigastric pain that improves with meals
- Diagnostic endoscopic biopsy shows ulcer with hypertrophy of Brunner glands
27
Crohn disease
- Chronic inflammatory condition of unknown etiology
- May affect any part of the GI tract but most commonly involves the distal ileocecum, small intestine, or colon
- Can lead to carcinoma involving the small intestine, or colon
- Wall involvement: full-thickness inflammation with knife-like fissures
- Present with right lower quadrant pain (ileum) with non-bloody diarrhea
- Linear ulceration of the mucosa
- Cobblestone appearance, creeping fat, and strictures ('string-sign' on image)
28
Meckel diverticulum
- Most common congenital anomaly of the small intestine
- Outpouching of all three layers of bowel wall - true diverticulum
- Arises to du failure of vitelline duct to involute
- "Rule of 2s": seen in 2% of the population, 2 inches long, and located in small bowel within 2 feet of ileocecal valve
- Present with bleeding, volvulus, intussusception, or obstruction during first 2 years of life
29
Intussusception
- Telescoping of proximal segment of bowel into distal segment
- Associated with leafing edge:
* In children, most common cause is lymphoid hyperplasia
* In adults, most common cause is tumor
30
Volvulus
- Twisting of bowel along its mesentery
- Result in obstruction and disruption of blood supply
- Most common locations are sigmoid colon (elderly) and cecum (young adults)
31
Celiac disease
- Immune-mediated damage of small bowel villi due to gluten exposure
- Blunting of small intestinal villi, presence of IgA endomysial and anti-tissue transglutaminase antibodies
- Antibodies directed against gliadin and transglutaminase --> suggest both genetic and immune-mediated mechanism
- Associated with HLA DQ2 and DQ8 (B8 and DW3)
- Hypersensitivity type IV reaction, delayed type - helper T cells mediate tissue damage
- Present with weight loss, weakness, and diarrhea with pale, bulky, frothy, foul-smelling stools
- More common in patients with type I DM
32
Neuroendocrine (carcinoid) tumors
- Occur most frequently in the appendix
- Localized to the small intestine in about 30% of cases
- Characteristically slow-growing, are of low-grade malignancy, and may metastasize
33
Hirschsprung disease
- Dilation of the colon (congenital megacolon)
- Due to absence of ganglion cells of the submucosal and myenteric neural plexus
- Associated with Down syndrome
- Clinical features is based on obstruction; failure to pass meconium, empty rectal vault on DRE, massive dilation of bowel proximal to obstruction with risk for rupture
34
Colonic diverticula
- Outpouchings of mucosa and submucosa through muscularis propria
- Related to wall stress
* Associated with constipation and low-fiber diet; commonly seen in older adults
* Arise where vasa recta traverse muscularis propria (weak point in colonic wall); sigmoid is most common location
- Almost always multiple
- Diverticulosis - diverticula without inflammation
- Divertivulitis - inflammation of diverticula
35
Ischemic bowel disease
- Atherosclerotic occlusion of at least two of the major mesenteric vessels
- Most often affected are the splenic flexure and the rectosigmoid junction
- Result in mucosal, mural, or transmura infarction involving the wall of the intestine
36
Angiodysplasia
- Tortous dilation of small vessels spanning the intestinal mucosa or submucosa
- Usually arises in cecum and right (ascending) colon du to high wall tension
- Extremely common cause of otherwise unexplained lower bowel bleeding
37
Ulcerative colitis
- Grouped along with Crohn disease as inflammatory bowel disease
- Unknown etiology
- Wall involvement: mucosal and submucosal ulcers
- Location: begins in rectum and can extend proximally up to cecum
- Present with left lower quadrant pain with bloody diarrhea
- Crypt abscesses with neutrophils
- Red, granular appearance of the mucosa
- Gross appearance: pseudopolyps, loss of hausfrau ('lead pipe' sign on imaging)
- Complications: toxic megacolon, perforation of the colon, colorectal adenocarcinoma
38
Pseudomembranous colitis
- Superficial grayish mucosal exudates consisting of necrotic, loosely adherent mucosal debris
- Caused by overgrowth of exotoxin-producing Clostridium difficile
- Clinical: fever, toxicity, and diarrhea
- Most often occurring in patients on broad-spectrum antibiotic therapy
39
Amebic colitis
- Infection of the colon with Entamoeba histolytica
| - Characterized by flask-shaped ulcers
40
Benign polyps
- Pedunculated polyps - attached by a narrow stem
- Sessile polyps - broad-based attachment
(1) Hyperplastic polyps - most common type of polyp, can occur anywhere in the colon or small intestine
(2) Inflammatory polyps - include benign lymphoid polyps and inflammatory pseudopolyps consisting of granulation tissue and remnants of mucosa
(3) Hamartomatous polyps
* Juvenile polyps - occur in small intestine and colon, most often occur in children
* Peutz-Jeghers polyps
41
Adenomatus polyps
- True neoplasms, 2nd most common type of colonic polyp
(1) Tubular adenomas:
* Most comon type (75%) of adenomatous polyp
* Small and pedunculated
* Contain malignant foci
(2) Tubulovillous adenomas:
* 15% of adenomatous polyps
* Resemble tubular adenomas, but have a surface covered by fingerlike villi
(3) Villous adenomas:
* Larger than tubular adenomas, usually sessile and velvety, and are characterized by large numbers of fingerlike villi
* Highest potential for malignancy of all of the adenomatous polyps
(4) Sessile serrated adenomas:
Resembles hyperplastic polyps, but they are precursors to malignancy
* Predilection for the right colon and often show microsatellite instability
42
Adenocarcinoma of the colon and rectum
- Most common neoplasms in the Western world
- Associated with increased serum concentration of carcinoembryonic antigen (CEA) - most useful for following the course of the disease
- Adenoma-carcinoma sequence:
* APC mutations increase risk for formation of polyp
* K-ras mutations lead to formation of polyp
* p53 mutation and increased expression of COX allow for progression to carcinoma
- Some develops not through the APC pathway, but through defects in mismatch repair genes; seen in HNPCC or Lynch syndrome
- Predisposing factors: adenomatous polyps, inherited multiple polyposis syndromes, long-standing ulcerative colitis, genetic factors, low-fiber diet that is high in animal fat
- Astler-Coller classification
43
Acute appendicitis
- Acute inflammation of appendix; most common cause of acute abdomen
- Related to obstruction of the appendix by lymphoid hyperplasia (children) or fecalith (adults)
- Present with periumbilical pain, fever, and nausea
- Pain localizes to right lower quadrant
44
Plummer- Vinson syndrome
- Iron deficiency; usually older women
- Resent decrease in incidence
- Iron deficiency (its presumed cause), dysphagia, and esophageal webs + often angular stomatitis, atrophic tongue, and brittle nails
- Long-standing - a risk of postcricoid esophageal carcinoma
45
Granular cell tumor (esophagus)
- Small, subepithelial mass
- Usually arises in the distal esophagus, more often i women
- Polygonal or spindle cells with abundant granular eosinophilic cytoplasm
- May induce a florid "pseudoepitheliomatous" response in the overlying squamous epithelium
46
Leiomyoma (esophagus)
- Most common benign tumor if the esophagus
- Symptomatic cases less common than carcinoma
- Symptomatic leomyomas - solraty intramural masses usually less than 5 cm in diameter; some may be pedunculated
47
Whipple disease
- Tropheryma whippelii (Actinomycetae)
- Small intestinal mucosa with macrophages laden with bacilli
- Bacilli-laden macrophages in synovia, brain, heart, joints, skin, etc.
- Present with diarrhea, abdominal pain, wight loss, and joint pain
- Malabsorption
- Extrenely rare
