Gastrointestinal Flashcards
What is a tracheoesophageal fistula? How does it present? What is the most common variant?
A congenital defect resulting in an abnormal connection between the esophagus and trachea
Presents with vomiting, polyhydramnios, abdominal distention and aspiration
The most common variant consists of proximal esophageal atresia with the distal esophagus arising from the trachea
What is an esophageal web? How does it present?
Thin protrusion of esophageal mucosa most often in the upper esophagus
Presents with dysphagia for poorly chewed food
What protrudes in an esophageal web? What is there an increased risk for?
The esophageal mucosa
Increased risk for esophageal squamous cell carcinoma
What is Plummer-Vinson syndrome?
Characterized by severe iron deficiency anemia, esophageal web, and beefy-red tongue due to atrophic glossitis (atrophy of the mucosa and exposed blood vessels)
Also has an increased risk for esophageal squamous cell carcinoma
What is a Zenker diverticulum? How does it present?
An outpouching of pharyngeal mucosa through an acquired defect in the muscular wall (false diverticulum - only protruded one part of the wall)
Presents with dysphagia, obstruction and halitosis (food gets trapped and rots)
Mallory-Weiss syndrome: what is it, what causes it, how does it present
Longitudinal laceration of mucosa at the gastroesophageal junction (GE)
Caused by severe vomiting, usually due to alcoholism or bulimia
Presents with painful hematemesis
Where do the following occur:
Mallory-Weiss syndrome
Plummer-Vinson syndrome
Zenker diverticulum
Mallory-Weiss syndrome: gastroesophageal junction (GE) (laceration of the mucosa)
Plummer-Vinson syndrome: esophagus (esophageal web)
Zenker diverticulum: pharynx (outpouching of pharyngeal mucosa)
Boerhaave syndrome
Rupture of the esophagus leading to air in the mediastinum and *subcutaneous emphysema (can push on skin on the neck and feel air bubbles). Seen with sever Mallory-Weiss syndrome.
Esophageal varices: what are they? what causes them? risk?
Dilated submucosal veins in the lower esophagus
Arise secondary to portal hypertension: distal esophageal vein normally drains into portal vein via the left gastric vein. In portal HTN, the left gastric vein backs up into the esophageal vein resulting in dilation (varices).
Asymptomatic but risk of rupture: presents w/ *painless hematemesis, most common cause of death in cirrhosis
What is the most common cause of death in cirrhosis? How does it present?
Rupture of esophageal varices
Presents with *painless hematemesis
Where does the esophageal vein normally drain? What is the significance of this?
The left gastric vein which drains to the portal vein
In portal HTN this gets backed up leading to esophageal varices
What is achalasia? What is it due to? Clinical features?
Meaning “without relaxation” it is disordered esophageal motility with inability to relax the lower esophageal sphincter (LES)
Due to damaged ganglion cells in the myenteric plexus: can be idiopathic or secondary to a known insult (Trypanosoma cruzi infection in Chagas diease)
Clinical features: dysphagia for s/l, putrid breath (rotting food), *high LES pressure on esophageal manometry, ‘bird-beak’ sign on barium swallow study, increased risk for esophageal squamous cell carcinoma
Where are the ganglion cells of the myenteric plexus located? What is there function? What disorder are they associated with?
Between the inner circular and outer longitudinal layers of the muscular is propria
Important for regulating bowel motility and relaxing the LES
Damaged in Achalasia
‘Bird-beak’ sign on barium swallow study?
Achalasia
Gastroesophageal reflux disease (GERD): clinical features
Reflux of acid from the stomach due to reduced LES tone
Clinical features: heartburn, asthma (adult-onset) and cough, damage to enamel of teeth, ulceration with stricture and Barrett esophagus
Risk factors for GERD
OH, tobacco, obesity, fat-rich diet, caffeine, and *hiatal hernia
What is the most common type of hiatal hernia? What is another type?
Sliding (stomach into esophagus) - most common
Paraesophageal (stomach is next to esophagus)
What is Barrett esophagus?
Metaplasia of lower esophageal mucosa from stratified squamous epithelium to *nonciliated columnar epithelium with goblet cells. Seen in 10% of patients w/ GERD - response of the lower esophagus stem cells to acidic stress
Is Barrett esophagus harmless?
No - is may progress to dysplasia and adenocarcinoma
What are the two types of esophageal carcinoma?
Adenocarcinoma
Squamous cell carcinoma
Adenocarcinoma of the esophagus:
What is it?
Where is it most common?
How does it arise?
Malignant proliferation of glands
Most common type of esophageal carcinoma in the West
Arises from preexisting Barrett esophagus; usually involves the lower one-third* of the esophagus
Squamous cell carcinoma of the esophagus: What is it? Where is it most common? Where does it arise? What are the major risk factors?
Malignant proliferation of squamous cells
Most common esophageal cancer worldwide
Usually arises in the upper or middle third of the esophagus
Major risk factors: OH, tobacco, very hot tea (Iran/China), achalasia (rotting food), esophageal web (Plummer-Vinson) esophageal injury (ex/ lye ingestion - hair straightening chemical)
Lymph node spread in esophageal cancer
Upper 1/3: cervical nodes
Middle 1/3: mediastinal or tracheobronchial nodes
Lower 1/3: celiac and gastric nodes
Presentation of squamous cell carcinoma of the esophagus
Progressive dysphagia, WL, pain and hematemesis
As well as, hoarse voice (recurrent laryngeal nerve involvement) and cough (tracheal involvement)
What is gastroschisis?
Meaning “to split”
Congenital malformation of the anterior abdominal wall leading to exposure of abdominal contents
Omphalocele
Persistent herniation of bowel into the umbilical cord. Due to failure of herniated intestines to return to the body cavity during development. *Contents are covered by peritoneum and amnion of the umbilical cord
What is Pyloric stenosis? How does it present? Treatment?
Congenital hypertrophy of pyloric smooth muscle; more common in males
Classically presents two weeks after birth: projective nonbilious vomiting, visible peristalsis, olive-like mass in the abdomen
Treatment is myotomy (muscle is cut out)
Acute gastritis:
Cause
Acidic damage to stomach mucosa. Due to imbalance between mucosal defenses and acidic environment. Defenses include mucin layer production by foveal cells, bicarbonate secretion by surface epithelium, and normal blood supply (provides nutrients and picks up leaked acid)
Acute gastritis risk factors
Severe burn (Curling ulcer) - hypovolemia leads to decreased blood supply
NSAIDs (decreased PGE2 - normally decreases acid and increases mucus, bicarb and blood flow)
Heavy alcohol consumption (toxin directly damages mucosa)
Chemotherapy (knocks out turnover cells)
Increased intracranial pressure (Cushing ulcer) - increased stimulation of vagus nerve leads to increased acid production (ACh - parietal cells)
Shock - multiple (stress) ulcers may be seen in ICU patients
Acid damage in acute gastritis can result in inflammation, erosion or ulcer. What is the difference between erosion and ulcer?
Erosion - loss of superficial epithelium
Ulcer - loss of mucosal layer
What are the two types of chronic gastritis? Which is more common?
Chronic autoimmune gastritis
Chronic H. pylori gastritis (more common, 90%)
Chronic autoimmune gastritis is due to autoimmune destruction of what cells? Where are they located?
Due to autoimmune destruction of gastric parietal cells which are located in the stomach body and fundus
What antibodies are associated with autoimmune chronic gastritis? What is the pathogenesis?
Antibodies against parietal cells and/or intrinsic factor (side effect, not a cause); useful for diagnosis but pathogenesis is mediated by T cells (type IV hypersensitivity)
Clinical features of autoimmune chronic gastritis
Atrophy of mucosa with intestinal metaplasia
Achlorhydria with increased gastrin levels (loss of feedback) and antral G-cell (make gastrin) hyperplasia
Megaloblastic (pernicious) anemia due to lack of intrinsic factor (parietal cells make intrinsic factor that binds B12)
*Increased risk for gastric adenocarcinoma (intestinal type)
Chronic H. pylori gastritis: Mechanism Most common site How does it present Treatment/Testing
Due to H. pylori-induced acute and chronic inflammation; H. pylori ureases and proteases along with inflammation weaken mucosal defenses
Antrum is the most common site
Presents with epigastric abdominal pain
Treatment involves triple therapy: resolves gastritis/ulcer and reverses intestinal metaplasia
Negative urea breath test and lack of stool antigen confirm eradication of H. pylori
H. pylori gastritis has increased risk for…
Ulceration (peptic ulcer disease)
Gastric adenoma (intestinal type)
MALT lymphoma
Peptic ulcer disease:
Locations - where is most common
Solitary mucosal ulcer involving either the proximal duodenum (90%) or distal stomach (10%)
Causes of duodenal ulcer
Almost always H pylori (95%), rarely may be due to ZE (gastinoma, excess gastrin causes parietal cells to produce excess H+)
How does a duodenal ulcer present? How do you diagnose it? Where does it usually arises and what are the possible complications?
Epigastric pain that improves with meals (duodenum increase defense/neutralizing substances w/ a meal)
Diagnostic endoscopic biopsy shows ulcer with hypertrophy of Brunner glands (produce mucus)
Usually arises in anterior duodenum; when present in the posterior duodenum rupture may lead to bleeding from the gastoduodenal artery or acute pancreatitis
Causes of gastric ulcer
How does it present?
Where is it usually located?
Rupture leads to risk of bleeding from which artery?
H pylori (75%), NSAIDs, bile reflux
Presents w/ epigastric pain that worsens with meals
Usually located on the lesser curvature of the antrum
Rupture carries risk of bleeding from left gastric artery
Peptic ulcer disease and risk of carcinoma
Duodenal ulcers are almost never malignant (duodenal carcinoma is extremely rare)
Gastric ulcers can be caused by gastric carcinoma (intestinal subtype)
How to differentiate gastric ulcers (benign vs. malignant)
Gastric ulcers can be caused by gastric carcinoma (intestinal subtype)
Benign peptic ulcers are usually small (), and surround by flat mucosa (not folded up)
Malignant ulcers are large and irregular with heaped up margins (piling up mucosa)
Biopsy is required for definitive diagnosis
Gastric carcinoma
Malignant proliferation of surface epithelial cells (adenocarcinoma)
Sub-classified into intestinal (more common) and diffuse types
Intestinal type (gastric carcinoma):
How does it present?
Most common site
Risk factors
Presents as a large, irregular ulcer with heaped up margins, most commonly involves the lesser curvature of the antrum (similar to gastric ulcer)
Risk factors: intestinal metaplasia (H pylori, autoimmune gastritis), nitrosamines in smoked foods (Japan), and blood type A
Diffuse type (gastric carcinoma):
Characterized by?
Not associated with?
Characterized by signet ring cells that diffusely infiltrate the gastric wall; desmoplasia (growth of fibrous or CT) results in thickening of the stomach wall (linitis plastica)
Not associated with H pylori, intestinal metaphase or nitrosamines
What lymph nodes does gastric cancer spread to?
left supraclavicular node (Virchow node)
How does gastric carcinoma present?
Presents late with WL, abdominal pain, anemia and early satiety
Rarely presents as acanthosis nigricans or Leser-Trelat sign (patient gets dozens of seborrheic keratosis)
Where does gastric carcinoma metastasize to?
Most commonly the liver Periumbilical region (Sister Mary Joseph nodule) - seen with intestinal type Bilateral ovaries (Krukenberg tumor) - seen with diffuse type
Duodenal atresia:
What is it associated with?
Clinical features
Congenital failure of duodenum to canalize; associated with Down syndrome
Clinical features: polyhydamnios, distention of stomach and blind loop of duodenum (‘double bubble’ sign), bilious vomiting
Double bubble sign is associated with what?
Duodenal atresia
Meckel diverticulum
What is it? How does it arise?
Outpouching of all three layers of the bowel wall (true diverticulum)
Arises due to failure of the vitelline duct to involute (how the midgut receives nutrients from the yolk sac, involutes the seventh week)
Volvulus:
What is it?
What does it result in?
Where are the common locations?
Twisting of the bowel along its mesentery
Results in obstruction and disruption of the blood supply with infarction
Most common locations are sigmoid colon (elderly) and cecum (young adults)
What is the ‘rule of 2s’ with Meckel’s diverticulum?
Seen in 2% of the population (most common congenital anomaly of the GI tract)
2 inches long and located in the small bowel within 2 feet of the ileocecal valve
Can present during the first 2 years of life with bleeding (due to heterotopic gastric mucosa), volvulus intussusception, or obstruction (mimics appendicitis); most cases are asymptomatic
Most common causes of intussusception in adults and children?
Adults: tumor
Children: lymphoid hyperplasia (Peyer’s patches) (e.g., rotavirus); usually arises in the terminal ileum leading to intussusception into the cecum
What is currant jelly stool seen with?
Intussusception
Small bowel is highly susceptible to ischemic injury (needs a lot of ATP for digestion/absorption). How can infarction occur? What are the clinical features?
Transmural infarction occurs with thrombosis/embolism of the superior mesenteric artery or thrombosis of the mesenteric vein
Mucosal infarction occurs with marked hypotension
Clinical features: abdominal pain, bloody diarrhea, decreased bowel sounds
Lactose intolerance:
What is it?
How does it present?
How is the deficiency acquired?
Decreased function of the lactase enzyme found in the brush border of enterocytes (lactose normally breaks down lactose into glucose and galactose)
Presents with abdominal distention and diarrhea upon consumption of milk products; undigested lactose is osmotically active
Deficiency may be congenital (rare AR) or acquired (late childhood). Temporary deficiency is seen after small bowel infarction (lactase is highly susceptible to injury)
Celiac disease:
What is it?
Associated with what HLA type?
What is the pathogenic component?
Immune-mediated damage of small bowel villi due to gluten exposure
Associated with HLA-DQ2 and DQ8
Gliadin is the most pathogenic component
Pathogenesis of Celiac disease (how does gliadin mediate damage)
Once absorbed, gliadin is deamidated by tissue transglutaminase (tTG)
Deamidated gliadin is presented by antigen presenting cells via MHC class II
Helper T cells mediate tissue damage
What is the clinical presentation of celiac disease in adults and children? What skin disorder is associated with this disease?
Children: abdominal distention, diarrhea and failure to thrive
Adults: chronic diarrhea and bloating
Small herpes-like vesicle may arise on the skin (dermatitis herpetiformis) due to IgA deposition at the tips of dermal papillae; resolves with gluten-free diet
Laboratory findings in celiac disease
What is found on a duodenal biopsy?
IgA antibodies against endomysium, tTG, or gliadin; IgG antibodies are also present and are useful for dx in individuals with IgA deficiency (increased incidence of IgA deficiency is seen in celiac disease)
Duodenal biopsy reveals flattening of villi, hyperplasia of crypts and increased intraepithelial lymphocytes. *Damage is most prominent in the *duodenum; jejunum and ileum are far less involved
What are of the small bowel is most impacted in celiac disease?
Duodenum
What late complications present with refractory celiac disease?
Small bowel carcinoma
T-cell lymphoma
Tropical Sprue:
What is it?
What differentiates it from celiac disease?
Damage to small bowel villi due to an unknown organism resulting in malabsorption
Similar to celiac except:
-occurs in tropical regions (Caribbean)
-arises after infectious diarrhea and responds to antibiotics
-damage is most prominent in jejunum and ileum (secondary vitamin B12 or folate deficiency may ensue); duodenum less commonly involved
Whipple disease:
What is it? What organism is involved? What stain is positive?
Where is the classic site of involvement and what does this result in?
What are other common sites?
Systemic tissue damage characterized by macrophages loaded with Tropheryma whippeli organisms; partially destroyed organisms are present in macrophage lysosomes (positive for PAS)
Classic site of involvement is the small bowel lamina propria: macrophages compress lacteals, chylomicrons cannot be transferred from enterocytes to lymphatics, results in fat malabsorption and steatorrhea
Other common sites include synovium of joints (arthritis), cardiac valves, lymph nodes and CNS
Abetalipoproteinemia:
What is it?
What apolipoproteins are involved?
Clinical features
Autosomal recessive deficiency of apolipoprotein B-48 and B-100
Clinical features: malabsorption (due to defective chylomicron formation, requires B-48) and absent plasma VLDL and LDL (require B-100)
Carcinoid tumor: What is it? What do the tumor cells contain? What are they positive for? Where is the most common site? What is secreted? What is in the urine?
Malignant proliferation of neuroendocrine cells; low-grade malignancy
Tumor cells contain neurosecretory granules that are positive for *chromogranin
Can arise anywhere along the gut; *small bowel is the most common site (grows as a submucosal polyp-like nodule)
Often secretes serotonin - released into portal circulation and metabolized by the liver MAO into 5-HIAA which is excreted in the urine
What is carcinoid syndrome characterized by? What are triggers?
Characterized by bronchospasm, diarrhea and flushing
Symptoms can be triggered by OH or emotional stress which stimulate serotonin release from the tumor
Most common location for a carcinoid tumor?
Small bowel
When will you see carcinoid syndrome and carcinoid heart disease?
With a metastasis of the carcinoid tumor to the liver which allows serotonin to bypass liver metabolism
Serotonin is released into the hepatic vein and leaks into systemic circulation via hepato-systemic shunts, resulting in carcinoid syndrome and carcinoid heart disease
What is carcinoid heart disease?
Characterized by right-sided valvular fibrosis (increased collagen) leading to tricuspid regurgitation and pulmonary valve stenosis. Left-sided valvular lesions are not seen due to the presence of monoamine oxidase (metabolizes serotonin) in the lungs!
Which side of the heart is affected in carcinoid heart disease and why?
Characterized by right-sided valvular fibrosis (increased collagen) leading to tricuspid regurgitation and pulmonary valve stenosis. Left-sided valvular lesions are not seen due to the presence of monoamine oxidase (metabolizes serotonin) in the lungs!
What is the most common cause of acute abdomen?
Acute appendicitis (inflammation of the appendix)
What are the causes of appendicitis in adults and children? What are the clinical features?
Obstruction of the appendix by lymphoid hyperplasia (children) or a fecalith (adults)
Clinical features: Periumbilical pain, fever, N, pain eventually localizes to RLQ (McBurney point). Rupture results in peritonitis that presents with guarding and rebound tenderness. Periappendiceal abscess is a common complication
Hirschsprung disease: What is it? Cause Associated with what disease? Clinical features Treatment
Defective relaxation and peristalsis of rectum and distal sigmoid colon
Due to congenital failure of ganglion cells (neural crest-derived) to descend into myenteric and submucosal plexus
Associated with Down syndrome
Clinical features: failure to pass meconium, empty rectal vault on DRE, massive dilation of bowel (megacolon) proximal to obstruction with risk for rupture
Treatment: resection of the involved bowel; ganglion cells are present in the bowel proximal to the diseased segment
Where is the myenteric plexus located? The submucosal plexus? What do they regulate?
Myenteric (Auerbach) plexus is located between the inner circular and outer longitudinal muscle layers of the muscularis propria and regulates motility
Submucosal (Meissner) plexus is located in the submucosa and regulates blood flow, secretions and absorption
What is unique about the biopsy for Hirschsprung disease?
It is a rectal suction biopsy - mucosa and submucosa (standard biopsy only gets the mucosa which does not have ganglion cells)
The biopsy will reveal a lack of ganglion cells
Ulcerative Colitis: Wall involvement Location Symptoms Inflammation Gross appearance Imaging
Wall involvement: mucosal and submucosal ulcers
Location: Begins in rectum and can extend up to the cecum (continuous)
Symptoms: LLQ pain (rectum), bloody diarrhea
Inflammation: *Crypt abscesses with neutrophils
Gross appearance: Pseudopolyps, loss of haustra
Imaging: Lead pipe sign
Crohn disease: Wall involvement Location Symptoms Inflammation Gross appearance Imaging
Wall involvement: Full-thickness inflammation w/ knife-like fissures
Location: Anywhere from mouth to anus with skip lesions (terminal ileum most common, rectum least common)
Symptoms: RLQ pain (ileum) with non-bloody diarrhea
Inflammation: *Lymphoid aggregates with granulomas
Gross appearance: Cobblestone mucosa, creeping fat and strictures
Imaging: String-sign
Imaging: String-sign Lead pipe Bird beak Double bubble
String-sign: Crohn disease
Lead pipe: UC
Bird beak: Achalasia
Double bubble: Duodenal atresia
Smoking: Crohns vs. UC
Protects against UC
Increases risk for Crohn disease
Complications UC vs. Crohn disease
UC: Toxic megacolon and carcinoma (risk based on extent of colonic involvement and duration of disease, usually a not a concern until after 10 years of the disease)
Crohn: Malabsorption with nutritional deficiency, calcium oxalate nephrolithiasis, fistula formation, and carcinoma if colonic disease is present
Extraintestinal manifestations (Crohn vs. UC)
Crohn: Ankylosing spondylitis, sacroiliitis, migratory polyarthritis, uvetitis, erythema nodosum, pyoderma gangrenosum, aphthous ulcers, kidey stones
UC: Ankylosing spondylitis, p-ANCA, primary sclerosing cholangitis, pyoderma gangrenosum, erythema nodosum, aphthous ulcers, uveitis
Angiodysplasia:
What is it?
Where does it arise?
How does it present?
Acquired malformation of mucosal and submucosal capillary beds
Usually arises in the cecum and right colon due to high wall tension
Rupture classically presents as hematochezia in an older adult
Hereditary hemorrhage telangiectasia:
What is it?
Dominant or recessive?
How does it present?
Autosomal dominant disorder resulting in thin-walled blood vessels, especially in the mouth and GI tract
Rupture presents as bleeding
Ischemic colitis: What is it? Most common location? Most common cause? How does it present?
Ischemic damage to the colon, usually at the splenic flexure (watershed area of superior mesenteric artery)
Atherosclerosis of SMA is the most common cause
Presents with postprandial pain and weight loss; infarction results in pain and bloody diarrhea
Irritable bowel syndrome:
What is it?
Cause?
Pathologic changes?
Relapsing abdominal pain with bloating, flatulence and change in bowel habits (diarrhea or constipation) that improves with defecation; classically seen in middle aged females
Related to disturbed intestinal motility; no identifiable pathologic changes
Increased dietary fiber may improve symptoms
Colonic diverticula:
What is it?
Cause?
Location
Outpouchings of mucosa and submucosa through the muscularis propria (false diverticulum)
Related to wall stress: associated with constipation, straining, and low-fiber diet; commonly seen in older adults
Arise where the vasa recta transverse the muscularis propria (weak point in colonic wall); sigmoid colon is the most common location
Usually asymptomatic; complications include: rectal bleeding, diverticulitis (due to obstruction of fecal mater, presents with appendicitis-like symptoms in the LEFT lower quadrant), fistula (inflamed diverticulum ruptures and attaches to a local structure)
What would air or stool in the urine indicate?
Colovesicular fistula (rupture of an inflamed diverticulum that attaches to the bladder)
Colonic polyps:
What are they?
What are the most common types?
Raised protrusion of colonic mucosa
Most common types are hyperplastic (most common) and adenomatous
Hyperplastic polyps: Cause Appearance Location Benign or Malignant?
Hyperplastic polyps are due to hyperplasia of the glands
Classically show a serrated appearance on microscopy
Usually arise in the left colon (rectosigmoid)
Benign with no malignant potential
Adenomatous polyps:
Cause
Benign or Malignant?
Due to neoplastic proliferation of glands
Benign but premalignant; may progress to adenocarcinoma via the adenoma-carcinoma sequence
What is the adeno-carcinoma sequence?
The molecular progression from normal colonic mucosa to adenomatous polyp to carcinoma
- APC (adenomatous polyposis coli gene) mutations (sporadic or germline) increase risk for formation of polyp
- K-ras mutation leads to formation of polyp
- p53 mutation and increased expression of COX allow for progression to carcinoma; aspirin impedes progression from adenoma to carcinoma
What chromosome is the APC gene on?
Chromosome 5
Role of aspirin in adeno-carcinoma sequence
Impedes progression from adenoma to carcinoma (decreases COX)
How do hyperplastic and adenomatous polyps look on colonoscopy?
Identical - all are removed and examined microscopically
Greatest risk for progression from adenoma to carcinoma is related to size > 2 cm, sessile growth and villous histology
Familial adenomatous polyposis (FAP): AD or AR? What is it? What is the mutation in? On what chromosome? What is done?
AD disorder characterized by 100s to 1000s of adenomatous colonic polyps
Due to inherited APC mutation (chromosome 5); increases propensity to develop adenomatous polyps through colon and rectum
Colon and rectum are removed prophylactically; otherwise all patients develop carcinoma by 40 years of age
Gardner syndrome
FAP with fibromatosis and osteomas
- Fibromatosis is a non-neoplastic proliferation of fibroblasts; arises in retroperitoneum (desmoid) and locally destroys tissues
- Osteoma is a benign tumor of bone that usually arises in the skull
Turcot syndrome
FAP with CNS tumors (medulloblastoma and glial tumors)
Juvenile polyp: What is it? How does it present? Juvenile polyposis: Location Risk
Sporadic, hamartomatous (benign) polyp that arises in children (<5), usually presents as as solitary rectal polyp that prolapses and bleeds
Juvenile polyposis is characterized by multiple juvenile polyps in the stomach and colon; large numbers of juvenile polyps increase the risk of progression to carcinoma
Peutz-Jeghers syndrome:
What is it?
AD or AR?
Increased risk for?
Hamartomatous (disorganized but normal tissue - benign) polyps throughout the GI tract and mucocutaneous hyperpigmentation (freckle-like spots) on lips, oral mucosa, and genital skin; AD
Increased risk for colorectal, breast and gynecologic cancer
Colorectal carcinoma: What is it? Peak incidence? Screening? Tumor marker - useful for what?
Carcinoma arising from colonic or rectal mucosa
Peak incidence in 60-70 years of age
Screening via colonoscopy and fecal occult blood test; begins at 50
CEA is a serum tumor marker - useful for assessing treatment response and detecting recurrence; not useful for screening
Staging of colorectal cancer (TNM)
T - depth of invasion; tumors limited to the mucosa generally do not spread due to lack of lymphatics in the mucosa
N - spread to regional lymph nodes
M - distant spread; most commonly involves the liver
Left vs. right-sided colorectal carcinoma
Left: grows as a napkin-ring lesion; presents with decreased stool caliber, LLQ pain and a blood-streaked stool
Right: grows as a raised lesion; presents with iron deficiency anemia (occult bleeding) and vague pain. An older adult with iron deficiency anemia has colorectal carcinoma until proven otherwise
Colonic carcinoma is associated with an increased risk for…
Streptococcus bovis and endocarditis
What is the microsatellite instability pathway (MSI)?
Microsatellites are repeating sequences of noncoding DNA; integrity of sequence (stability) is maintained during cell division
Instability indicates defective DNA copy mechanisms (e.g., DNA mismatch repair enzymes)
Hereditary nonpolyposis colorectal carcinoma (HNPCC) is due to inherited mutations in DNA mismatch repair enzmyes
What cancers are HNPCC patients at risk for?
Colorectal, ovarian, and endometrial carcinoma
How does colorectal cancer in HNPCC patients arise?
De novo (not from adenomatous polyps) at a relatively early age, usually right-sided
How does cleft lip and palate form?
Due to failure of facial prominences to fuse
Cleft lip - failure of fusion of maxillary and medial nasal prominences (formation of primary palate)
Cleft palate - failure of fusion of the two lateral palatine processes or failure of fusion of lateral palatine process with the nasal septum and/or median palatine process (formation of secondary palate)
Cleft lip and palate usually occur together
Aphthous ulcer:
What is it?
When does it occur?
How does it look?
Painful, superficial ulceration of the oral mucosa
Arises in relation to stress and resolves spontaneously but often recurs
Characterized by a grayish base (granulation tissue) surrounded by erythema
Behcet syndrome:
What is it?
Cause?
Recurrent aphthous ulcers, genital ulcers and uveitis
Due to IC vasculitis involving small vessels
Can be seen after a viral infection but etiology is unknown
Oral herpes:
Cause
Where does the virus remain dormant?
Vesicles involving oral mucosa that rupture resulting in shallow, painful, red ulcers
Usually due to HSV-1
Primary infection occurs in childhood; lesions heal by virus remains dormant in ganglia of the trigeminal nerve
Stress and sunlight cause reactivation of the virus, leading to vesicles that often arise on the lips (cold sore)
Squamous cell carcinoma of the oral mucosa:
Risk factors
Most common location
Precursor lesions
Malignant neoplasm of squamous cells lining the oral mucosa
OH and tobacco are major risk factors
Floor of the mouth is the most common location
Oral leukoplakia and erythroplakia are precursor lesions
What is leukoplakia? How can it be distinguished from candidiasis and hairy leukoplakia?
Leukoplakia is a white plaque that cannot be scraped away; often represents squamous cell dysplasia
Oral candidiasis (thrush) is a white deposit on the tongue which is easily scraped away, usually seen in immunocompromised states
Hairy leukoplakia is a white, rough (‘hairy’) patch that arises on the *lateral tongue. It is usually seen in immunocompromised individuals (AIDS) and its due to EBV-induced squamous cell hyperplasia; *not pre-malignant
What is erythroplakia?
Red plaque that represents vascularized leukoplakia and is highly suggestive of squamous cell dysplasia
Mumps virus infects which glands? What else can be infected? Risk?
Bilateral inflamed parotid glands
Orchitis, pancreatitis and aseptic meningitis (increased serum amylase from pancreas or parotid glands)
Orchitis carries risk of sterility, especially in teenagers
What is sialadentis? What is the most common cause and what does this lead to?
Inflammation of the salivary gland
Most commonly due to an obstructing stone (sialolithiasis) leading to Staphylococcus aureus infection; usually unilateral
Warthin tumor:
What is it and where does it arise?
Benign cystic tumor with abundant lymphocytes and germinal centers (lymph node-like stroma); 2nd most common tumor of the salivary gland
Almost always arises in the parotid gland
Mucoepidermoid carcinoma
Malignant tumor composed of mucinous and squamous cells; most common malignant tumor of the salivary gland
Usually arises in the parotid; commonly involves the facial nerve
What tumor of the salivary glands commonly involves the facial nerve?
Mucoepidermoid carcinoma
Pleomorphic adenoma:
What is it?
What gland does it occur in usually?
How does it present?
Benign tumor composed of stromal (e.g., cartilage) and epithelial tissue; most common tumor of the salivary gland
Usually arises in the parotid
Presents as a mobile, painless, circumscribed mass at the angle of the jaw
High rate of recurrence
Rarely, may transform into carcinoma, which presents with signs of facial never damage
Most common tumor of the salivary gland?
Pleomorphic adenoma
