GI julia Flashcards
MC congenital fistula
Tracheoesophageal Fistula
- feeding issues: bind pouch and food accumulates -> vomit
- breathing complication: as baby breathes, the air enters the lower part of esophagus to stomach + stomach inflates
Achalasia: definition and sx
- inability to relax LES = increased LES tone and APERISTALSIS
- mostly uncertain etiology
sx:
- dysphagia
- regurgitation
- chest pain
Hiatal hernia: definition and sx
- diaphragmatic muscular defect
- WIDENING of space through which the lower esophagus passes through to stomach
- hiatal hernias are ABOVE the stomach
- associated with reflux
- can lead to ulceration, bleeding, perforation, strangulation
Schatzki ring: definition, what is it found with
circular band of mucosal tissue at DISTAL esophagus
- causes narrowing
Diverticula of the esophagus: location and true diverticula def
Zencker – usually high/proximal
Traction – usually mid esophagus
Epiphrenic – usually distal esophagus/low
true diverticula: have all 4 layers in the
Mallory-Weiss tear
severe secondary to severe vomiting: alcoholics, bulimia
– mucosal tears is LONGITUDINAL on lower esophagus
Esophageal varices: common areas portal/caval anastomoses (where portal and systematic connects)
Definition: Dilated submucosal veins in the lower esophagus
- secondary to portal hypertension (90% of cirrhosis pts)
- can lead to MASSIVE, sudden and fatal hemorrhage
Three common areas of portal/caval anastomoses (where portal and systematic connects)
- Esophageal
- Umbilical
- Hemorrhoidal
esophagitis causes
- GERD/reflux -> leads to barretts
- barretts
chemical:
- lye: suicide attempts with strictures
- alcohol
- hot drinks
- chemo
infectious:
- CANDIDA esophagitis: immunocompromised patients (e.g. AIDS) – white, creamy coating
- Herpes esophagitis: can cause ULCERS
GERD definition and what can be seen histologically for dx
definition: Reflux of acid from the stomach due to reduced LES tone
- reflux esophagitis
- main sx: heartburn
- slowed reflux clearing and delayed gastric emptying
- complication: Barrett’s esphagus
Dx: inflammatory cells
- EOSINOPHILS
- neutrophils
- lymphocytes
Barrett’s esophagus: definition, cause, and major complication
Definition: Metaplasia of lower esophageal mucosa from stratified squamous epithelium to
columnar epithelium with GOBLET cells
- metaplastic to protect itself from acid reflux
– intestinal mucosa produces MUCIN which helps neutralize acid (goblet cells)
- Long standing metaplasia -> dysplasia-> esophageal ADENOCARCINOMA**
Esophageal tumors: benign types
leiomyomas (smooth muscle tumor) - often found in uterus**
others: lipoma, condylomas (HPV), fibrovascular polyps, “granulation tissue”
Esophageal tumors: malignant types and their risk factors
SCC MC
- risk factors: TOBACCO, ALCOHOL, nitrites in fungi, Betel nuts
– progression is usually from DYSPLASIA of squamous cells to squamous cell carcinoma-in-situ to infiltrative/invasive cancer
Adenocarcinoma = Barrett’s esophagus major risk factor
- usually occurs distally
Pyloric stenosis presentation and risk factors
Presentation:
- congenital hypertrophy of pyloric smooth muscle
- projectile vomiting in infants
- presence of palpable mass in epigastrium “olive”
- M > F
- risk factors: whites, premature birth, fam hx, smoking during pregnancy
Tx: myotomy
Acute gastritis definition and risk factors and what does it cause on histology
definition: Acidic damage to the stomach mucosa
- causes HEMORRHAGE and EROSIONS + NEUTROPHILS (inflammatory response)
Risk factors
- NSAIDS
- alcohol, smoking
- chemotherapy
- severe stress: trauma, burn, surgery, shock
Chronic gastritis: how does it compare to acute gastritis
Chronic:
- no erosions, no hemorrhage
– mucosal changes: intestinal metaplasia, atrophy (thinning of mucosa), dysplasia
- LYMPHOCYTES present (chronic inflammation)
acute:
- neutrophils
- hemorrhage
- erosions
Chronic gastritis: what are the types of gastritis
Chronic H pylori gastritis * (90%):
Chronic autoimmune gastritis * (10%): antibodies against parietal cells and intrinsic factor (pernicious anemia + B12 deficiency)
others:
- toxins: alcohol/smoking
- post-surgical: bile reflux
- radiation
- Crohn’s: granulomatous
- eosinophilic esophagitis: middle aged women
- allergic gastritis: children
- lymphocytic gastritis: diffuse
H. pylori can lead to what illnesses
- chronic gastritis
- peptic ulcers: 80% of gastric peptic ulcers, 100% of duodenal peptic ulcers
- adenocarcinoma of stomach
- MALT lymphoma of stomach
tx: triple therapy abx
Peptic ulcers: MCC and other causes; main sx and complication
MCC: H. pylori
- 80% of gastric peptic ulcers
- 100% of duodenal peptic ulcers.
others: NSAIDS, stress
sx:
- burning, aching
- epigastric pain
- iron deficiency anemia
- main complications: perforate, acute hemorrhage, obstruction from edema/scarring
peptic ulcers: complication
bleeding: 15-20% of pts
- MC complication
- first indication of ulcer
perforation:
- radiation to back, chest, LUQ
- 2/3 of ulcer deaths
- rarely first indication of ulcer
obstruction from edema:
- 2% of pts
- incapacitating crampy ab pain
- rare: total obstruction with intractable vomit
Acute ulcers
usually small < 1cm, superficial, multiple
Due to : NSAIDS or stress
Stress: endogenous steroids vs exogenous steroids
- endogenous: release of stress hormones during burns, shock, massive trauma, sepsis
- exogenous: high dose corticosteroid tx, cushing ulcer
Hypertrophic gastropathies: main sx/presentation and what are the pain gastropathies
stomach rugae are prominent* (cerebriform)
- usually no inflammation
- marked hyperplasia of mucosa
main types:
- Menetrier’s disease
- Zollinger-Ellison syndrome
- hypertrophic -hypersecretory gastropathy
Zollinger-Ellison syndrome vs Menetrier’s disease
Menetrier’s disease:
- hyperplasia of surface mucus cells
- associated with: elevation of TGF-alpha
Zollinger-Ellison syndrome:
- gastric gland hyperplasia secondary to excessive gastrin secretion from a gastrinoma (pancreas tumor)
Stomach tumors: benign
leiomyomas: smooth muscle
polyps (hyperplastic vs adenomatous)
- PPI pts tend to get polyps
lipomas: adipose tissue
stomach tumor: malignant vs potentially malaignant
malignant:
- adenocarcinoma MCC (H. pylori); SIGNET RING CELLS
- lymphoma: MC = B cell type MALToma -> can treat by tx H. pylori
potentially malignant:
- GIST: gastrointestinal stromal tumor, SPINDLE CELLS, CELLS OF CAJAL, c-KIT
- carcinoid tumor (neuroendocrine
Malignant – Adenocarcinoma of stomach risk factors types and major cell type found in that cancer type
Risk factors:
- H. pylori
- geographic and socioeconomic factors
- nitrites
- smoked and pickled foods
- chronic gastritis
- smoking
- fam hx
Types:
- intestinal type: usually presents as a mass – different forms
- linitis plastica (“leather bottle”): diffuse infiltration of stomach walls by malignant SIGNET cells, poor prognosis
GIST – gastrointestinal stromal tumor
Solitary, circumscribed fleshy mass
- Size and location important for prognosis
- Small lesions do better and don’t usually recur
cell type:
- SPINDLE CELLS: look like smooth muscle or nerve tissue
- derived from Interstitial cells of Cajal (innervated network of intestinal pacemaker cells for gut peristalsis)
- cKit positive chemo marker!!!! can give IMATINIB - tyrosine kinase inhibitor
Congenital problems of small/large intestine: list
- duplication of segments in GI tract
- malrotation: increase volvulus risk
- atresia/stenosis: partial or complete blockage (atresia) or narrowing (stenosis) of the gastrointestinal lumen
- Omphacele: ventral wall defect where the intestines, liver, and sometimes other organs remain outside the abdomen, contained WITHIN A SAC
- Gastroschisis : infant’s intestines protrude out of the body through an opening near the UMBILICAL CORD, WITHOUT covered by protective sac, paraumbilical
- Meckel’s diverticulum: MC congenital
- Hirschsprung’s disease
Meckel’s diverticulum: definition, causes, presentation
Outpouching of all three layers of the bowel wall = true diverticulum:
- cause: failure of the vitelline duct to obliterate
– usually in terminal ileum on antimesenteric side
rule of 2s:
- 2% of population (MC congenital anomaly of the GI tract!!!)
- 2 inches long and located in the small bowel within 2 feet of the ileocecal valve
- often clinically silent
- When symptomatic: abdominal pain or sx of GI or bowel obstruction.
Hirschsprung’s disease: major sx, cause, complication
cause: absence of GANGLION cells in segment of bowel = aperistalsis
- usually infant fails to pass meconium
- Most prominent symptom is CONSTIPATION in first 2 months of life
- May also present with vomiting, abdominal pain, distention, diarrhea, poor weight gain, and slow growth
Complications:
- enterocolitis
- megacolon
- bowel obstruction
- intestinal perforation
Celiac disease
immune-mediated damage of small bowel villi due to gluten exposure!!!!
- gluten: present in wheat and grains, oats, barley; its most pathogenic component is gliadin
- T lymphocytes are immobilized
- histology: villous flattening (atrophy) in duodendum
- malabsoprtion sx due to no villi: bloating, greasy stool, flatulence
Tx: no gluten diet.
Whipple’s disease
infectious disease caused by Tropheryma whipplei (rod-shaped bacilli)
- Dx: SI biopsies detecting PAS-positive foamy macrophages in the lamina propria
- dense accumulation of distended, foamy macrophages into SI lamina propria –> contains periodic acid (Schiff (PAS)-positive) in granules
Rare multisystem inflammatory disease
- first sx: malabsorption in small intestine - stearrhea
- affects the joints, central nervous system, and cardiovascular system
celiac ds: increased risk of what
- increased risk of malignancy!! - MC cancer: enteropathy associated T cell lymphoma
tropical sprue
Celiac ds in tropical regions
- Acquired
- Unsure etiology but epidemic
- not related to gluten
Whipple’s disease
Systemic tissue damage characterized by macrophages loaded with Tropheryma
whippelii organisms (rod-shaped bacilli)**
- rare multisystem inflammatory disease: joints, CNS, and cardiovascular system
- distended macrophages in lamina propria
- risk factor: Occupational exposure to soil or animals - white farmers
Villi are full of tropheruyma whipplei -> lymphatic obstruction -> MALABSORPTION SX
- triad: diarrhea, wt loss, arthralgia
Disaccharidase deficiencies: what type of diarrhea
lactose is most common, causes osmotic diarrhea
- acquired not congenital
Abetalipoproteinemia
- autosomal recessive
- inability to make chylomicrons from free fatty acids and monoglycerides -> cannot absorb adek fat soluble vitamins + fat malabsoprtion
- Infant presents with failure to thrive, diarrhea, steatorrhea.
viral entrocolitis: MCC
MC: rotovirus
– the virus infects and destroys mature enterocytes in small intestine
Bacterial enterocolitis
Bacterial enterocolitis – ingestion of bacterial toxins (Staph., Vibrio, Clostridum), ingestion of bacteria which produce toxins (e.g. E. coli), infections by enteroinvasive bacteria (enteroinvasive E. coli, Shigella, C. difficile).
E. coli – many subtypes, may produce toxins, invasive; usually watery diarrhea, some types cause hemorrhage.
Salmonella – food borne
Shigella – hemorrhagic, not usually food borne, person-to-person contact
Campylobacter – toxins, invasive, food borne
Yersinia – food, invasive, lymphoid reactions
Vibrio – non-invasive, watery, enterotoxin
C. difficile – cytotoxin, nosocomial (usually antibiotic related), aka pseudomembranous colitis
parasitic enterocolitis
Nematodes (Roundworms) such as Ascaris, Strongyloides, etc.
Cestodes (tapeworms), Giardia (G. lamblia) infection by cyst of single-cell organism, worldwide prevalence.
Diarrhea types and main causes
- secretory: viral damage to mucosa, bacterial endotoxin, laxatives
- osmotic: disaccharidase deficiencies, too. much solutes in lumen
- exudative: bacterial damage to mucosa, IBD
- malabsorptive: celiac, whipple, steorrhea
- motility
Inflammatory Bowel Disease – Crohn’s versus ulcerative colitis and which has greater cancer risk
Crohn:
- can form fistulas -> fecal madder in urine
- Terminal ileum: B12 malabsorption
- Skip areas
- transmural inflammation
- GRANULOMAS
UC:
- Just mucosa NOT transumural
- No malabsorption
- Not terminal ilium
- No skip areas just colon -> more risk for colon cancer adenocarcinoma
- crypt abscesses on microscope*
- pseudopolyps*: represent regenerating mucosa
Ischemia/infarct of bowel: what is the main hallmark, common presentation, causes
hallmark: Hemorrhagic Necrosis!!!
- mucosal necrosis -> transmural
- may see pseudomembranes histologically (similar to C. difficile colitis)
common presentation:
- elderly who have cardiovascular problems because cause is usually thrombus to vessel supplying intestine
- pt presents with severe, sudden abdominal pain with rigid abdomen
other causes:
- shock
- CHF: decreased perfusion
- arterial thrombus/emboli
- venous thrombus
- mechanical
IBD: common features of UC vs crohns
Angiodysplasia: def and main issue
NOT dysplasia – twisted, dilated submucosal vessels which may RUPTURE
– similar to AVM (arteriovenous malformation)
- Rupture classically presents as hematochezia in an older adult
Hemorrhoids
due to chronically elevated increased submucosal venous pressure, increased abdominal pressure
- ex: valsalva
Diverticulosis/diverticulitis definition, associated factors
full thickness (all 4 layers) outpocketings
related to wall stress:
-Associated with increased luminal pressure
- older age
- decreased fiber in diet
- weakening in wall
- In Japan, diverticulosis is more common on the right side due to higher fiber diets, while in Western countries it often affects the left side.
diverticulosis/Diverticulitis complications
- impaction
- inflammation
- perforation -> peritonitis
- bleeding: silent or fatal
- obstruction
Formation of Colonic Diverticula
- Vessels are very close to diverticula
- Resemble hernias of the colonic wall: form at the entry points of mucosal arteries through the muscularis.
- Represents weak spots that develop due to high colonic intraluminal pressure, often related to a low-fiber diet.
Obstructions in small and large intestine
caused by adhesions, impaction, hernias, volvulus (twisting), intussusception, tumors, IBD
volvulus: sigmoid colon (elderly) and cecum (young adults)
- hx of ab surgery, hernia repair
INTUSSUSCEPTION:
- Telescoping of proximal segment of bowel forward into distal segment
- kids: MC location in terminal ilium with lymphoid hyperplasia -> lymphatic tissue to fight infections
Intestinal tumors – Colonic polyps types, which are more cancerous
- hyperplastic: non-neoplastic, SERRATED appearance on histo
- adenomatous: dysplastic -> could lead to cancer
- sessile > pedunculated: more risk of cancer -> flat on top of mucosa
- pedunculated: on stalk, can snip it off
- villous > tubular: VILLOUS MORE CANCEROUS
biggest risk of adenoma to cancer: sessile, villous, over 2 cm
Colon adenocarcinoma: genetic causes
loss of APC gene: tumor suppressor
k-RAS mutations: oncogene
loss of p53: tumor suppressor
activation of telomerase: infinite replication
Colon adenocarcinoma risk factors and pathogenesis/growth pattern
risk factors:
- family history
- age: over 50
- low fiber, high meat, refined carbs diet
pathogenesis:
- from pre-existing adenomatous polyp : dysplasia -> infiltration -> metastasis
-or can arise de-novo
- growth pattern: polypoid, annular (constricting), diffuse
Anal canal cancer: MCC and type
usually SCC related to HPV!!!
- worse prognosis
Mucocele and major complication
cyst in appendix filled with mucus!!
- may rupture and lead to pseudomyxoma peritonei (spread of mucinous material throughout the peritoneal cavity)
(mucinous cystadenoma and mucinous cystadenocarcinoma can also cause pseudomyxoma peritonei )
appendicitis/ other appendiceal lesions
- may have obstruction by fecalith
- NEUTROPHILS are present microscopically in muscularis to make diagnosis
- May perforate leading to peritonitis
Other appendiceal lesions:
- mucocele
- mucinous cystadenoma
- mucinous cystadenocarcinoma (last two are rare)
