2. Lower GI Pathology Flashcards
Intestinal obstruction
• Obstruction of the gastrointestinal tract may occur at any ____
• Collectively, ____, intestinal adhesions, intussusception, and
volvulus account for 80% of mechanical obstructions
• Clinical manifestations of intestinal obstruction include abdominal ____ and distention, vomiting, and constipation
level
hernias
pain
- Hernias
- Any weakness or defect in the abdominal wall may permit protrusion of a serosa- lined pouch of ____ called a hernia sac
- Adhesions
- ____ bridges that develop between bowel segments, abdominal wall, or operative sites
- Volvulus
- Twisting of a loop of bowel about its ____ point of attachment resulting in both luminal and ____ compromise
- Intussusception
- A length of intestine “swallows” part of the bowel ____ to it; this swallowed portion is drawn down until it can go no further because of attachment to ____
- Most common cause of intestinal obstruction in children younger than ____ years of age
peritoneum fibrous mesenteric vascular proximal mesentery 2
Ischemic bowel disease
- Injury to the bowel caused by insufficient ____ regardless of etiology
- High mortality for ____ ischemic disease (70%)
- Mucosal or submucosal infarctions (mural) can follow ____
- Transmural infarction is caused by acute ____ obstruction
- Patients experience severe abdominal pain that persists for more than ____ to 3 hours
blood flow acute hypoperfusion vascular 2
Watershed zone
• Small bowel has collateral blood vessels in the ____ so that slow progressive blood loss can be tolerated
• However, intestinal segments at the ends of their respective arterial supplies are susceptible to ____; acute compromise of major vessel can lead to ____ of several meters of intestine
• The splenic flexure is an area of ____ blood supplies where both the superior and inferior ____ arterial circulations terminate
• During systemic hypotension, ischemic injury occurs most often at the ____ flexure
periphery ischemia infarction overlapping mesenteric splenic
Celiac disease
• Multisystem disorder caused by an immune response to dietary ____ and related proteins
• The ____ soluble part of gluten, gliadin, contains the most disease- producing components
• Presents most commonly between ages of ____ and 60
• Associated with chronic ____, bloating, or fatigue
• Characterized by anemia due to chronic ____ and vitamin malabsorption
gluten alcohol 30 diarrhea iron
Celiac Disease
- Microscopic findings show variable degrees of ____ atrophy and chronic inflammation
- Complete resolution of gastrointestinal pathology with strict gluten- free ____
- Individuals with celiac disease have a higher rate of ____
- 20-fold higher risk for enteropathy-associated ____
- 30-fold higher risk for small intestinal ____
- 2- to 4-fold higher risk for oropharyngeal and esophageal ____
villous atrophy diet malignancy T-cell lymphoa adenocarcinoma carcinoma
Oral manifestations
• Can be associated with delay in dental ____, reduction of salivary flow, recurrent ____, angular cheilitis, and dental enamel defects in primary and permanent teeth
• Dental defects tend to occur ____ and chronologically in all four quadrants, with the most defects seen in the maxillary and mandibular ____ and ____
• Teeth may be ____ with white, yellow, or brown spots
• Other defects may include poor ____ formation, pitting or banding of teeth, and
mottled or translucent-looking teeth
• Dental enamel defects less frequently seen in ____, however in adults oral problems related to Celiac disease include
• Recurent ____, atrophic glossitis, xerostomia, or ____ of the oropharynx
eruption aphthous stomatitis symmetrically incisors molars discolored enamel adults aphthous stomatitis SCC
Infectious enteritis (Whipple’s disease)
• An infection caused by ____ (an actinomycete) that most commonly affects the ____
• Most common in white ____, particularly farmers who have occupational exposure to soil or animals
• Patients present with triad of diarrhea, weight loss, and arthralgia
• Microscopically, small intestine biopsy shows villi with lamina propria
containing foamy ____ which contain bacterial inclusions
• These accumulations cause ____ obstruction which leads to the malabsorptive diarrhea
• Most patients respond to ____ (trimethoprim and sulfamethoxazole)
tropheryma whipplei proximal small bowel males macrophages lymphatic antibiotics
Escherichia coli
• E. coli are bacilli that colonize the ____ gastrointestinal tract; most are nonpathogenic, but a subset cause human disease
• There are different classifications according to morphology, mechanism of pathogenesis, and in vitro behavior
• Enterotoxigenic E. coli
• Known as ____ diarrhea spread via contaminated ____ or water
- Enteropathogenic E.coli
- More common in the ____ population
- Enterohemorrhagic E. coli
- O157:H7
- Non-O157:H7
- Enteroinvasive E. coli
- Enteroaggregative E. coli
- May induce diarrhea and ischemic bowel disease
healthy
traveler’s
food
pediatric
Enterohemorrhagic O157:H7
• Guts of ____ are a natural reservoir of this subtype of E.coli
• Especially cows that are standing around in ____ all day long
• E coli cannot survive long in ____
• Manure often is ends up in water systems
- Most common strain is ____
- 157th somatic antigen found on bacteria body
- 7th flagella antigen found
- Large outbreaks are associated with inadequately cooked ground ____
- Contaminated milk and vegetables are vehicles for infection
- O157:H7 strains are likely to cause ____ outbreaks, blood diarrhea, hemolytic- uremic syndrome, and ischemic colitis
- Antibiotics can kill the bacteria, but lead to increase of ____-like toxins that enhance the risk of ____ syndrome, especially in children
cows
manure
grass
O157:H7 beef large Shiga hemolytic-uremic
Pseudomembraneous colitis
- Due to a toxin produced by ____
- Also referred to as antibiotic-associated colitis
- While antibiotic-associated diarrhea may also be caused by other organisms such as Salmonella or Staphylococcus aureus only C.difficile causes ____
- Substantial number of cases have been associated with use of antibiotics, particularly ____ and clindamycin
- Likely disruption of the normal gut flora by ____ allows C.difficile overgrowth
clostridium difficile
pseudomembraneous colitis
lincomycin
antibiotics
Pseudomembraneous colitis
- Risk factors for C.difficile include advanced ____, hospitalization, and antibiotic treatment
- As many as 30% of hospitalized adults are colonized by C.difficile, a rate tenfold greater than the ____
- Patients present with fever, ____, abdominal pain, cramps, watery diarrhea, and dehydration
- Bloody diarrhea is ____
- ____ or vancomycin are generally effective therapies
age general population leukocytosis uncommon metronidazole
Enterobius vermicularis (pinworms)
- Most common ____ affecting humans
- School children and adolescents, especially those who live in ____, have the highest prevalence
- Worms do not invade tissue and live entire lives in ____, so generally asymptomatic
- However, adult worms living in intestine may migrate to the anal orifice at night and deposit ____ on the perirectal mucosa
- Irritation to eggs cause classic symptom is ____
- The infective larva-containing egg resides in dust and soil, and transmission is believed to be ____
- ____ and colitis have been described as secondary to pinworm infection
- Most infections clear ____ after several weeks
- ____ drugs may be indicated to prevent transmission to others, and for symptomatic cases
parasites institutions intestinal lumen eggs nocturnal pruritus ani fecal-oral appendicitis spontaneously antiparasitic
Irritable bowel syndrome (IBS)
• Characterized by a group of symptoms that occur together
• Repeated abdominal ____, changes in bowel habits, which may be diarrhea,
constipation, or both, and bloating
• Despite very real symptoms, the gross and microscopic evaluation is ____ in most IBS patients
• Diagnosis is based on ____
• Peak prevalence of IBS is between ____ and 40 years of age and there is
a significant ____ predominance
• ____ disease must be ruled out
pain normal symptoms 20 female inflammatory bowel disease
IBD
- Inflammatory bowel disease (IBD) is a disease that causes ____ of the gastrointestinal tract
- The two disorders that comprise IBD are ____ and Crohn disease
- In ulcerative colitis inflammation is limited to the ____ and ____ and is limited to ____ or ____, i.e. just the inner layer of the bowel wall
- In contrast, inflammation in Crohn disease may involve any ____ of the GI tract, and often is ____, i.e. involving all layers of the bowel wall
- Most often diagnosed in people between ages ____ and 30 years
chronic inflammation ulcerative colitis colon rectum mucosa submucosa area transmural 15
IBD
Symptoms
• Inflammatory bowel disease symptoms can range from very mild to very severe
• They include diarrhea, blood in the stool, abdominal pain, fever, fatigue, and weight loss
• Some symptoms of IBD result from inflammation of parts of the body outside of the ____
• These include ____ pain/arthritis, eye/vision problems, certain types of rashes, and liver disease
• ____ manifestations
• Often, symptoms can be ____ and then suddenly worsen during a ____,
which can require extra treatment
• Flares can be very ____, even life-threatening, if untreated because they may lead to severe ____, bleeding, or bowel perforation
GI tract joint oral stable flare dangerous infection
IBD
Treatment
• Treatment of IBD depends on how severe the disease is
• Mild disease is treated with ____ medications, which can be
taken either by mouth or as suppositories/enemas
• More severe disease is treated with ____ or immunosuppressant medications (often the same as those used for other ____ diseases)
• These can be taken by mouth, by injection under the skin, or by ____ infusion
• Flares often require ____ as extra treatment
• Patients with severe disease who do not get better with medications may require ____
• People with IBD that involves the colon are at increased risk of ____ and need to have routine colonoscopies throughout their lives
anti-inflammatory immunomodulator autoimmune intravenous steroids surgery colon cancer
IBD
Oral manifestations
• Orofacial ____
• Granulomatous inflammation that can be seen in association with inflammatory
bowel disease, in particular ____ disease
• Most frequent site of involvement is the ____, which present as persistent swelling
• Intraoral sites may present as hyperplastic mucosa in the mandibular ____
- Deep, granulomatous-appearing ulcers
- Often appear as ____ and develop in the ____
- Patchy ____ macules and plaques
- Pyostomatitis vegetans
- Characteristic yellowish ____ found on the oral mucosa
granulomatosis Crohn lips mucobuccal fold linear mucobuccal fold erythematous pustules
• Polyps are abnormal growths of ____ tissue that develop on mucous membranes
• They can be ____ (with a stalk) or sessile (broad based without a stalk)
• Intestinal polyps can be classified as non-neoplastic or neoplastic
• The non-neoplastic polyps can be further classified as ____,
hamartomatous, or ____
• Neoplastic polyps can be classified as ____ or sessile ____ adenomas
epithelial pedunculated inflammatory hyperplastic adenomatous serrated
Hyperplastic polyps
• Benign epithelial proliferations that are the most commonly encountered polyp in the adult ____
• Grossly, hyperplastic polyps are dome-shaped nodules that rarely grow beyond ____ mm in diameter
• They are often multiple and found in the ____ colon and rectum
• Because they may be endoscopically similar in appearance to small adenomatous polyps (malignant potential), hyperplastic polyps are often ____ for pathologic analysis
• No significant ____ alterations
colorectum 5 sigmoid removed genetic
Hamartomatous polyps
• Can occur ____ (non-neoplastic) or as a part of genetically determined or acquired syndrome, in which case they may be considered ____/pre-malignant
• Many hamartomatous polyp syndromes are caused by germline mutations in ____ genes or proto-oncogenes
• Some of these syndromes are associated with an increased ____ risk, either in the polyp, or in the extra-intestinal sites
• Hamartomatous polyposis syndromes
• ____ polyposis, Peutz-Jeghers syndrome, ____ syndrome
sporadically neoplastic tumor suppressor cancer juvenile cowden
Juvenile polyps
• Sporadic (benign) and syndromic forms of juvenile polyps are ____
• In sporadic form, polyps are ____
• In juvenile polyposis syndrome, there may be ____ polyps in the colon
• Majority sporadic polyps occur in children less than ____ years old, whereas patients with polyposis syndrome tend to be ____, with a mean age of 9.5 years
• Most common location is the ____, and presents as rectal bleeds
• Dysplasia is extremely ____ in sporadic polyps, in contrast, juvenile
polyposis syndrome is associated with ____
• 30 to 50% of patients with juvenile polyposis develop ____
indistinguishable solitary 3-100 5 older rectum rare dysplasia colonic adenocarcinoma
Juvenile polyposis syndrome
• Criteria for a diagnosis of syndromic juvenile polyposis
1. Greater than ____ juvenile polyps in the colon at one time
2. Presence of ____ juvenile polyps
3. Any number of juvenile polyps in a patient with a ____ of juvenile polyposis
- Autosomal dominant form
- No associated ____ abnormalities
- Nonfamilial form with associated congenital abnormalities
- ____disease, hydrocephalus, or intestinal ____
five
extracolonic
family history
congenital abnormalities
congenital heart
malrotation
Peutz-jeghers syndrome
• Autosomally ____ inherited syndrome characterized by gastrointestinal ____ polyps and pigmented macules of mucous membranes and skin
• More than 95% of patients with Peutz-jeghers syndrome demonstrate pigmentation of the mucocutaneous membranes at ____, specifically around the nose, lips, buccal mucosa, hands and feet, genitalia, and perianal region
• Lifetime cancer risk for patients with Peutz-jegher is estimated to be ____%
• Gastrointestinal, lung, breast, pancreas, uterus, ovary, cervix, and Sertoli cells of the testis
dominant
hamartomatous
birth
93
