Gastrointestinal - Pathology (1) Flashcards
1
Q
Salivary gland tumors
- Generally…
- Pleomorphic adenoma (benign mixed tumor)
- Warthin tumor (papillary cystadenoma lymphomatosum)
- Mucoepidermoid carcinoma
A
- Generally benign and occur in parotid gland
-
Pleomorphic adenoma (benign mixed tumor)
- The most common salivary gland tumor.
- Presents as a painless, mobile mass.
- Composed of chondromyxoid stroma and epithelium
- Recurs if incompletely excised or ruptured intraoperatively.
- Warthin tumor (papillary cystadenoma lymphomatosum)
- A benign cystic tumor with germinal centers.
-
Mucoepidermoid carcinoma
- The most common malignant tumor
- Has mucinous and squamous components.
- Typically presents as a painless, slow-growing mass.
2
Q
Achalasia
- Definition
- Barium swallow
- Associations
A
- Definition
- Failure of relaxation of LES due to loss of myenteric (Auerbach) plexus.
- A-chalasia = absence of relaxation.
- High LES opening pressure and uncoordinated peristalsis –> progressive dysphagia to solids and liquids (vs. obstruction—solids only).
- Failure of relaxation of LES due to loss of myenteric (Auerbach) plexus.
- Barium swallow
- Shows dilated esophagus with an area of distal stenosis.
- “Bird’s beak” [A].
- Associations
- Associated with an increased risk of esophageal squamous cell carcinoma.
- 2° achalasia may arise from Chagas disease.
3
Q
Esophageal pathologies
- Boerhaave syndrome
- Eosinophilic esophagitis
- Esophageal strictures
- Esophageal varices
- Esophagitis
A
- Boerhaave syndrome
- Transmural, usually distal esophageal rupture due to violent retching
- Surgical emergency.
- Eosinophilic esophagitis
- Infiltration of eosinophils in the esophagus in atopic patients.
- Food allergens –> dysphagia, heartburn, strictures.
- Unresponsive to GERD therapy.
- Esophageal strictures
- Associated with lye ingestion and acid reflux.
- Esophageal varices
- Painless bleeding of dilated submucosal veins in lower 1 ⁄3 of esophagus 2° to portal hypertension.
- Esophagitis
- Associated with reflux, infection in immunocompromised (Candida: white pseudomembrane; HSV-1: punched-out ulcers; CMV: linear ulcers), or chemical ingestion.
4
Q
Esophageal pathologies
- Gastroesophageal reflux disease
- Mallory-Weiss syndrome
- Plummer-Vinson syndrome
- Sclerodermal esophageal dysmotility
A
- Gastroesophageal reflux disease
- Commonly presents as heartburn and regurgitation upon lying down.
- May also present with nocturnal cough and dyspnea, adult-onset asthma.
- Decrease in LES tone.
- Mallory-Weiss syndrome
- Mucosal lacerations at the gastroesophageal junction due to severe vomiting.
- Leads to hematemesis.
- Usually found in alcoholics and bulimics.
-
Plummer-Vinson syndrome
- Triad of Dysphagia (due to esophageal webs), Iron deficiency anemia, and Glossitis (“Plumbers” DIG).
- Sclerodermal esophageal dysmotility
- Esophageal smooth muscle atrophy –> decreased LES pressure and dysmotility –> acid reflux and dysphagia –> stricture, Barrett esophagus, and aspiration.
- Part of CREST syndrome.
5
Q
Barrett esophagus (350)
- Definition
- Due to…
- Associated with…
A
- Definition
- Glandular metaplasia
- Replacement of nonkeratinized (stratified) squamous epithelium with intestinal epithelium (nonciliated columnar with goblets cells) in the distal esophagus [A].
- Due to…
- Chronic acid reflux (GERD).
- Associated with…
- Esophagitis, esophageal ulcers, and increased risk of esophageal adenocarcinoma.
6
Q
Esophageal cancer
- Possible carcinomas
- Worldwide
- in the United States
- Presentation
- Risk factors
A
- Can be squamous cell carcinoma or adenocarcinoma.
- Worldwide, squamous cell is more common.
- Squamous cell—upper 2 ⁄3.
- In the United States, adenocarcinoma is more common.
- Adenocarcinoma—lower 1 ⁄3.
- Worldwide, squamous cell is more common.
- Presentation
- Typically presents with progressive dysphagia (first solids, then liquids) and weight loss
- Poor prognosis.
- Risk factors include: (AABCDEFFGH)
- Achalasia
- Alcohol—squamous
- Barrett esophagus—adeno
- Cigarettes—both
- Diverticula (e.g., Zenker)—squamous
- Esophageal web—squamous
- Familial
- Fat (obesity)—adeno
- GERD—adeno
- Hot liquids—squamous
7
Q
Acute gastritis (erosive)
- Definition
- Can be caused by…
A
- Definition
- Disruption of mucosal barrier –> inflammation.
- Especially common among alcoholics and patients taking daily NSAIDs (e.g., patients with rheumatoid arthritis).
- Can be caused by…
- Stress
- NSAIDs
- Decreased PGE2 –> decreased gastric mucosa protection
- Alcohol
- Uremia
- Burns
- Curling ulcer—decreased plasma volume –> sloughing of gastric mucosa
- Burned by the Curling iron.
- Brain injury
- Cushing ulcer—increased vagal stimulation –> increased ACh –> increased H+ production
- Always Cushion the brain.
8
Q
Chronic gastritis (nonerosive)
- Type A
- Type B
- A vs. B
A
- Type A (fundus/body)
- Autoimmune disorder characterized by Autoantibodies to parietal cells, pernicious Anemia, and Achlorhydria.
- Associated with other autoimmune disorders.
- Type B (antrum)
- Most common type.
- Caused by H. pylori infection.
- Increased risk of MALT lymphoma and gastric adenocarcinoma.
-
A comes before B:
- Type A
- Autoimmune
- First part of the stomach (fundus/body).
- Type B
- H. pylori Bacteria
- Second part of the stomach (antrum).
- Type A
9
Q
Ménétrier disease
A
- Gastric hypertrophy with protein loss, parietal cell atrophy, and increased mucous cells.
- Precancerous.
- Rugae of stomach are so hypertrophied that they look like brain gyri.
10
Q
Stomach cancer
- Definition
- Intestinal
- Diffuse
- Virchow node
- Krukenberg tumor
- Sister Mary Joseph nodule
A
- Definition
- Almost always adenocarcinoma.
- Early aggressive local spread and node/liver metastases.
- Often presents with acanthosis nigricans.
-
Intestinal
- Associated with H. pylori infection, dietary nitrosamines (smoked foods), tobacco smoking, achlorhydria, chronic gastritis.
- Commonly on lesser curvature
- Looks like ulcer with raised margins.
-
Diffuse
- Not associated with H. pylori
- Signet ring cells [A]
- Stomach wall grossly thickened and leathery (linitis plastica).
-
Virchow node
- Involvement of left supraclavicular node by metastasis from stomach.
-
Krukenberg tumor
- Bilateral metastases to ovaries.
- Abundant mucus, signet ring cells.
-
Sister Mary Joseph nodule
- Subcutaneous periumbilical metastasis.
11
Q
Peptic ulcer disease:
Gastric vs. duodenal ulcer
- Pain with meals / weight
- H. pylori infection
- Mechanism
- Other causes
- Risk of carcinoma
- Other
A
- Pain
- Gastric: Can be Greater with meals –> weight loss
- Duodenal: Decreases with meals –> weight gain
- H. pylori infection
- Gastric: In 70%
- Duodenal: In almost 100%
- Mechanism
- Gastric: Decreased mucosal protection against gastric acid
- Duodenal: Decreased mucosal protection or increased gastric acid secretion
- Other causes
- Gastric: NSAIDs
- Duodenal: Zollinger-Ellison syndrome
- Risk of carcinoma
- Gastric: Increased
- Duodenal: Generally benign
- Other
- Gastric: Often occurs in older patients
- Duodenal: Hypertrophy of Brunner glands
12
Q
Ulcer complications
- Hemorrhage
- Perforation
A
- Hemorrhage
- Gastric, duodenal (posterior > anterior).
- Ruptured gastric ulcer on the lesser curvature of the stomach –> bleeding from left gastric artery.
- An ulcer on the posterior wall of the duodenum –> bleeding from gastroduodenal artery.
- Perforation
- Duodenal (anterior > posterior).
- May see free air under the diaphragm [A] with referred pain to the shoulder.
13
Q
Malabsorption syndromes
- Can cause…
- Syndromes
A
- Can cause…
- Diarrhea, steatorrhea, weight loss, weakness, and vitamin and mineral deficiencies.
-
These Will Cause Devastating Absorption Problems.
- Tropical sprue
- Whipple disease
- Celiac sprue
- Disaccharidase deficiency
- Abetalipoproteinemia
- Pancreatic insufficiency
14
Q
Tropical sprue
A
- Malabsorption syndrome
- Similar findings as celiac sprue (affects small bowel), but affects the entire small intestine and responds to antibiotics.
- Cause is unknown, but seen in residents of or recent visitors to tropics.
15
Q
Whipple disease
A
- Malabsorption syndrome
- Infection with Tropheryma whipplei (gram positive)
- PAS (+) foamy macrophages in intestinal lamina propria, mesenteric nodes.
- Cardiac symptoms, Arthralgias, and Neurologic symptoms are common.
- Most often occurs in older men.
- Foamy Whipped cream in a CAN.
16
Q
Celiac sprue
- Definition
- Findings
- Diagnosis
- Treatment
A
- Definition
- Malabsorption syndrome
- Autoimmune-mediated intolerance of gliadin (wheat) leading to malabsorption and steatorrhea.
- Decreased mucosal absorption that primarily affects distal duodenum and/or proximal jejunum.
- Associated with HLA-DQ2, HLA-DQ8, and northern European descent.
- Associated with dermatitis herpetiformis.
- Findings
- Anti-endomysial, anti-tissue transglutaminase, and anti-gliadin antibodies
- Blunting of villi
- Lymphocytes in the lamina propria [A].
- Moderately increased risk of malignancy (e.g., T-cell lymphoma).
- Diagnosis
- Serum levels of tissue transglutaminase antibodies are used for diagnosis.
- Treatment
- Gluten-free diet.
20
Q
Inflammatory bowel diseases:
Crohn disease
- Possible etiology
- Location
- Gross morphology
- Microscopic morphology
- Complications
- Intestinal manifestation
- Extraintestinal manifestations
- Treatment
- Mnemonic
A
- Possible etiology
- Disordered response to intestinal bacteria.
- Location
- Any portion of the GI tract, usually the terminal ileum and colon.
- Skip lesions, rectal sparing.
- Gross morphology
- Transmural inflammation –> fistulas.
- Cobblestone mucosa, creeping fat, bowel wall thickening (“string sign” on barium swallow x-ray [A]), linear ulcers, fissures.
- Microscopic morphology
- Noncaseating granulomas and lymphoid aggregates (Th1 mediated).
- Complications
- Strictures (leading to obstruction), fistulas, perianal disease, malabsorption, nutritional depletion, colorectal cancer, gallstones.
- Intestinal manifestation
- Diarrhea that may or may not be bloody.
- Extraintestinal manifestations
- Migratory polyarthritis, erythema nodosum, ankylosing spondylitis, pyoderma gangrenosum, aphthous ulcers, uveitis, kidney stones.
- Treatment
- Corticosteroids, azathioprine, methotrexate, infliximab, adalimumab.
- Mnemonic
- For Crohn, think of a fat granny and an old crone skipping down a cobblestone road away from the wreck (rectal sparing).
21
Q
Inflammatory bowel diseases:
Ulcerative colitis
- Possible etiology
- Location
- Gross morphology
- Microscopic morphology
- Complications
- Intestinal manifestation
- Extraintestinal manifestations
- Treatment
- Mnemonic
A
- Possible etiology
- Autoimmune.
- Location
- Colitis = colon inflammation.
- Continuous colonic lesions, always with rectal involvement.
- Gross morphology
- Mucosal and submucosal inflammation only.
- Friable mucosal pseudopolyps with freely hanging mesentery [B].
- Loss of haustra –> “lead pipe” appearance on imaging.
- Microscopic morphology
- Crypt abscesses and ulcers, bleeding, no granulomas (Th2 mediated).
- Complications
- Malnutrition, sclerosing cholangitis, toxic megacolon, colorectal carcinoma (worse with right-sided colitis or pancolitis).
- Intestinal manifestation
- Bloody diarrhea.
- Extraintestinal manifestations
- Pyoderma gangrenosum, erythema nodosum, 1° sclerosing cholangitis, ankylosing spondylitis, apthous ulcers, uveitis.
- Treatment
- ASA preparations (sulfasalazine), 6-mercaptopurine, infliximab, colectomy.
- Mnemonic
- Ulcerative colitis causes ULCCCERS:
- Ulcers
- Large intestine
- Continuous, Colorectal carcinoma, Crypt abscesses
- Extends proximally
- Red diarrhea
- Sclerosing cholangitis
24
Q
Diverticulum
- Definition
- “True” diverticulum
- “False” diverticulum or pseudodiverticulum
A
- Definition
- Blind pouch [A] protruding from the alimentary tract that communicates with the lumen of the gut.
- Most diverticula (esophagus, stomach, duodenum, colon) are acquired and are termed “false” in that they lack or have an attenuated muscularis externa.
- Most often in sigmoid colon.
-
“True” diverticulum
- All 3 gut wall layers outpouch (e.g., Meckel).
-
“False” diverticulum or pseudodiverticulum
- Only mucosa and submucosa outpouch.
- Occur especially where vasa recta perforate muscularis externa.
26
Q
Diverticulitis
- Definition
- Symptoms
- Treatment
A
- Definition
- Inflammation of diverticula classically causing LLQ pain, fever, leukocytosis [B].
- Sometimes called “left-sided appendicitis” due to overlapping clinical presentation.
- Symptoms
- May perforate –> peritonitis, abscess formation, or bowel stenosis.
- Stool occult blood is common +/– hematochezia.
- May also cause colovesical fistula (fistula with bladder) –> pneumaturia.
- Treatment
- Give antibiotics.
27
Q
Zenker diverticulum
- Definition
- Symptoms
A
- Definition
- Pharyngoesophageal false diverticulum [A].
- Herniation of mucosal tissue at Killian triangle between the thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor.
- Most common in elderly males.
- Presenting symptoms
- Dysphagia, obstruction, foul breath from trapped food particles (halitosis).
28
Q
Meckel diverticulum
- Definition
- Symptoms
- Diagnosis
- Mnemonic
A
- Definition
- True diverticulum.
- Persistence of the vitelline duct.
- May contain ectopic acid–secreting gastric mucosa and/or pancreatic tissue.
- Most common congenital anomaly of the GI tract.
- Symptoms
- Can cause melena, RLQ pain, intussusception, volvulus, or obstruction near the terminal ileum.
- Contrast with omphalomesenteric cyst = cystic dilation of vitelline duct.
- Diagnosis
- Pertechnetate study for uptake by ectopic gastric mucosa.
-
The five 2’s:
- 2 inches long.
- 2 feet from the ileocecal valve.
- 2% of population.
- Commonly presents in first 2 years of life.
- May have 2 types of epithelia (gastric / pancreatic).
29
Q
Intussusception
- Definition
- Age
A
- Definition
- “Telescoping” of 1 bowel segment into distal segment, commonly at ileocecal junction.
- Compromised blood supply –> intermittent abdominal pain often with “currant jelly” stools.
- Age
- Unusual in adults (associated with intraluminal mass or tumor that acts as lead point that is pulled into the lumen).
- Majority of cases occur in children (usually idiopathic; may be associated with recent enteric or respiratory viral infection).
- Abdominal emergency in early childhood.
30
Q
Volvulus
- Definition
- Location
A
- Definition
- Twisting of portion of bowel around its mesentery
- Can lead to obstruction and infarction.
- Can occur throughout the GI tract.
- Midgut volvulus more common in infants and children.
- Sigmoid volvulus more common in elderly.
34
Q
Colonic polyps
- Definition
- Adenomatous
- Malignancy
- Symptoms
A
- Definition
- Masses protruding into gut lumen –> sawtooth appearance.
- 90% are non-neoplastic.
- Often rectosigmoid.
- Can be tubular [A] or villous [B].
- Adenomatous
- Malignancy
- Adenomatous polyps are precancerous.
- Malignant risk is associated with increased size, villous histology, increased epithelial dysplasia.
- Precursor to colorectal cancer (CRC).
- The more villous the polyp, the more likely it is to be malignant
- Villous = villainous.
- Polyp symptoms
- Often asymptomatic, lower GI bleed, partial obstruction, secretory diarrhea (villous adenomas).
- Malignancy
36
Q
Colorectal cancer
- Epidemiology
- Risk factors
- Presentation
- Diagnosis
A
- Epidemiology
- Most patients are > 50 years old.
- ~ 25% have a family history.
- Risk factors
- IBD, tobacco use, large villous adenomas, juvenile polyposis syndrome, Peutz-Jeghers syndrome.
- Presentation
- Rectosigmoid > ascending > descending.
- Ascending—exophytic mass, iron deficiency anemia, weight loss.
- Descending—infiltrating mass, partial obstruction, colicky pain, hematochezia.
- Rarely presents as Streptococcus bovis bacteremia.
- Right side bleeds; left side obstructs.
- Rectosigmoid > ascending > descending.
- Diagnosis
- Iron deficiency anemia in males (especially > 50 years old) and postmenopausal females raises suspicion.
- Screen patients > 50 years old with colonoscopy or stool occult blood test.
- “Apple core” lesion seen on barium enema x-ray [A].
- CEA tumor marker: good for monitoring recurrence, not useful for screening.
38
Q
Molecular pathogenesis of CRC
- There are 2 molecular pathways that lead to CRC:
- Order of gene events
A
- There are 2 molecular pathways that lead to CRC:
- Microsatellite instability pathway (~15%):
- DNA mismatch repair gene mutations –> sporadic and HNPCC syndrome.
- Mutations accumulate, but no defined morphologic correlates.
- APC/β-catenin (chromosomal instability) pathway (∼85%)
- –> sporadic cancer.
- Microsatellite instability pathway (~15%):
- Order of gene events—AK-53.
- Normal colon
- –> Loss of APC gene
- Decreased intercellular adhesion and increased proliferation
- Colon at risk
- –> K-RAS mutation
- Unregulated intracellular signal transduction
- Adenoma
- –> Loss of tumor suppressor gene(s) (p53, DCC)
- Increased tumorigenesis
- Carcinoma
