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Path, Ass14
Lauren's Questions
97
Pathology
Graduate
02/25/2012

Additional Pathology Flashcards

 


 

Cards

Term
Esophagitis
Definition
Inflammation of the esophageal mucosa in the US and western countries: 5% of the adult population; immunocompromised > healthy individuals
Term
Esophagitis - Clinical Features
Definition
Acute inflammation, superificial necrosis, ulceration,and granulation tissue formation and fibrosis, located near the esophagus
Term
Bacterial esophagitis
Definition

Bacterial invasion of the lamina propria: 10-15% of cases of infectious esophagitis;

*necrosis of squamous epithelium, may occur in patients with systemic and upper respiratory tract infections

Term
Viral esophagitis
Definition
Most common cause of acute infectious esophagitis
Term
Herpes esophagitis
Definition

Etiology: immunocompromised patients;

Key features include - Shallow sharply punched out ulcers, surrounded by relatively normal mucosa;

 

Multinucleated giant cells with intranuclear cowdry type A inclusions at the margin of the ulcer and inclusions in the *squamous epithelial cells with characteristic ground glass nuclei or nuclear molding

Term
Cytomegalovirus esophagitis
Definition

Etiology: relatively common in AIDS patients, rare in immunocompetent pts.

Characteristic Ulcers: Multiple *well circumscribed ulcers, intranuclear nnd cytoplasmic inclusions found in the capillary endothelium* and stromal cells at the base of the ulcer.

Aancillary IHC stains and/or in situ hybridization may be useful for diagnosis

Term
Fungal Esophagitis
Definition

Etiology: mostly Candida albicans and tropicalis;

Occurs in immunosuppresed patients, may be found in otherwise healthy individuals;

 

Seen in AIDS pts when T cells are very low;

Term
Candida Esophagitis
Definition

At endoscopy of esophagus: white plaques of fibrinopurulent exudate*

 

This fungus is a normal part of GI tract flora.

 

Need to ID pseudohyphae with invasion and not just budding yeasts

Term
Candida tropicalis
Definition
More virulent form of Candida that can cause increased invasion by pseudohyphae in candida esophagitis
Term
Silver stain
Definition

Use this stain on candida albicans to visualize the fungal growths as dark black spots on a blue background;

 

In general, silver stains are used to visualize fungi and Legionella

Term
Infectious esophagitis
Definition

Less common causes of this disease:

Mycobacterium tuberculosis, MAC, Histoplasma caapsulatum, toxoplasma gondii, EBV, idiopathic esophageal ulceration, and HIV retrovirus

Term
Acute Gastritis
Definition

Possible etiology of inflammation of the stomach include: systemic viral or bacterial infections

(salmonella and CMV)

Term
Mucosal protection
Definition
Mucus secretion: diffusion coefficient for H+ that is 1/4 that of water: fluid containing acid and pepsin exit gastric glands in "jets", pass through the mucus layer without contact with the epithelial cells
Term
Acute Gastritis - describe the appearence of the gastric mucosa
Definition

Gross: punctuate erosions on the stomach surface,

 

Histo: Mucosal disruption with normal adjacent mucosa

Term
Chronic gastritis
Definition

Etiology: Chronic mucosal inflammatory changes in the stomach -> mucosal atrophy and intestinal metaplasia, usually in the absence of erosions:

 

H. Pylori* is the most important etiologic agent

Term
Chronic gastritis - describe the histological changes that take place
Definition
Histo: intestinal metaplasia and inflammation of the lamina propria (slide taken from stomach)
Term
Chronic active H. pylori gastritis
Definition

Microscopic features:

Neutrophils: more abundant in the *antrum and cardia* than corpus, only inflammatory cells in the gastric epithelium.

Acute cryptitis, and mixed with macrophages and eosinophils in lamina propria.

Lymphoid follicles are almost always present

Term
Antral-type H. pylori gastritis
Definition
H. pylori gastritis with high acid production, increased risk for duodenal ulcer
Term
Pangastritis H. pylori
Definition
H. pylori gastritis characterized by multifocal atrophy, lower acid secretion and increased risk for adenocarcinoma
Term
H. pylori gastritis - pathophysiology
Definition

Initial phase includes acute inflammatory response;

 

Endoscopically: hemorrhagic lesion, and multiple antral erosions and ulcers

Term
H. pylori
Definition

Characteristics: non-sporulating, curvilinear gram - rods, that flourish in gastric mucosa.

Flagella allow it to swim through the gastric mucous.

Elaborates urease, expresses bacterial adhesions and toxins;

Patients usually improve whne treated with antibiotics, relapsese are associated with re-infection

Term
H. pylori gastritis - mucosal appearence
Definition

Gross: No distinct endoscopic pattern; Hyperemia, erosions, hypertrophy and atrophy may coexist in varying combinations depending on the stage/type of gastritis;

 

Histology: Mucous layer covering the gastric mucosa is colonized by H. pylori, the organisms attach to the mucous cell

Term
PPIs
Definition

Proton Pump Inhibitors;

In H. pylori gastritis, patients on this drug may show histology with intracellular invasion by H. pylori

Term
Infectious colitis
Definition

Inflammation of the colon;

 

Histology: Diffuse, regional or focal active colitis with prominent cryptitis, without crypt architectural distortion or crypt abscess formation;

 

Use clinical questioning to separate this from IBD

Term
Viral gastroenteritis
Definition

Rotatavirus (MCC diarrhea in 6-24 m.o. worldwide),

Calcivirus = Norwalk virus (very common cause of nonbacterial food-borne epidermics (gastroenteritis) in all age groups,

Enteric adenovirus (diarrhea in infants)

Term
Viral gastroenteritis - pathophysiology
Definition

Pathology: viruses selectively infect and destroy mature enterocytes and cause villous atrophy and cryptal hyperplasia.

 

Viral particles may be present within villous enterocytes in EM

Term
Norovirus
Definition

aka Norwalk virus;

ssRNA;

Common cause of nonbacterial infecitous gasteroenteritis in all age groups;

Oral-fecal route of transmission;

 

Vomiting in children, diarrhea in adults; spreads in hospitals, nursing homes, and cruise ships

Term
Rotavirus
Definition

dsDNA virus;

Most common cause of severe diarrhea in infants and young children and a leading cause of diarrheal mortality in the world;

Only 10 virions required to inoculate (very virulent);

 

6-24 yr old individuals are most susceptible

Term
Rotavirus - pathophysiology of disease
Definition

Causes diarrhea by viral infection and destruction of mature enterocytes of the small bowel resulting in loss of absorptive surface → watery diarrhea.

 

There are vaccines now available

Term
Adenovirus
Definition

dsDNA (linear) genome, iscohedral capsule;

Second most common cause of pediatric diarrhea;

 

Biopsy is nonspecific;

Shows villous atrophy, crypt hyperplasia;

Incubation: 1 week;

 

Symptoms: diarrhea, vomiting, abdominal pain, fever, and weitght loss, recovery within 10 days (self limited)

Term
Viral gastroenteritis - histological appearence of the gastric mucosa
Definition

Histologically: Stomach has increased presence of lymphocytes and crypt hypertrophy;

 

Common causes include norovirus, rotavirus and adenovirus

Term
Gastric granulomas
Definition
Caused by infectious agents: TB, syphillis, Whipple's disease (causes malabsorption), histoplasmosis (fungus), anisakiasis/strongyloids (nematodes)
Term
Granulomatous Gastritis - histological appearence
Definition

Characteristic giant cells surrounded by epitheloid cells in stomach;

Often secondary to other conditions;

 

May be able to identify TB or Fungi based on special stains/cultures

Term
Whipple's Disease
Definition

A rare, systemic disease caused by the bacterium Tropheryma whipplei;

Typically presents in middle age white males;

 

Sx: chronic weight loss, arthritis/joint pain, malabsorption and lymphadenopathy;

 

Small bowel is MC affected;

Endoscopically mucosal folds are thickened with yellow-white plaques;

Microscopically there is a massive infiltration of the lamina propria and submucosa with foamy macrophages**

 

Tx: Antibiotics = Penicillin, ampicillin or tetracycline;

Term
PAS stain
Definition

Stains glycogen and mucopolysaccrides;

 

Used to visualize foamy macrophages in the lamina propria and submucosa of pts with in Whipple's disease

Term
Bacterial enterocolitis
Definition

Etiology:

Ingestion of preformed toxins (S. aureus, Vibrio cholerae, C. perfrinigins, C. botulinium);

OR

Infection by toxigenic organisms (traveler's diarrhea, may cause diarrhea and dehydration, or dysentery),

OR

Infection by enteroinvasive organisms (dysentery)

Term
Vibrio cholerae and ETEC
Definition

These two bacteria have secretory toxins involved in bacterial enterocolitis;

 

V. cholerae: (G-, comma shaped, oxidase+) produces a toxin that permanetly activates the Gs subunit of a GPCR in the intestines causing ↑ cAMP levels causing profuse diarrhea with "rice water" stools;

 

EnteroToxogenic E. coli: causes Traveler's diarrhea (watery)

Term
Shigella dysenteriae and EHEC
Definition

These two bacteria have cytotoxins and are involved in bacterial enterocolitis;

 

Shigella: (non-lactose fermenter that invades the intestinal mucosa and causes bloody diarrhea, no flagella).  Shiga toxin (inhibits protein synthesis) produces severe and potentially deadly dysentery;

 

EHEC: includes O157:H7 (produces shiga-like toxin);

 

Both are associated with the development of Hemolytic Uremic Syndrome, HUS (anemia, thrombocytopenia, renal failure)

Term
Staphylococcus - toxin
Definition

G(+) cocci in clusters;

 

Has a bacteiral endotoxin that binds to antigen receptors in lymphocytes; found in bacterial enterocolitis

Term
Which Bacterial species are capable of invasion?
Definition

EIEC,

Shigella,

Salmonella,

Yersinia enterocolitica species

 

all do this in bacterial enterocolitis

Term
Vibrio cholerae
Definition

Comma shaped gram - bacteira;

Causes secretory (rice-water) diarrhea,

 

01 and 0139 serotypes are the most important

Term
Cholera toxin
Definition

MOA: Vibrios never invade the gut epithelium, but when cholera toxin is secreted, it induces dilute "rice water" diarrhea up to 14 L/ day, causing dehydraiton and electrolyte imbalance.

 

Cholera toxin is an AB toxin that is endocytosed and the A subunit carries out ADP ribosylation of the Gs subunit of the GPCR causing ↑↑ cAMP which causes massive excretion of water and electrolytes into the intestinal lumen;

 

The bacteria affect the proximal small intestine, but the intestinal mucosa is left intact.

Term
Salmonella
Definition

Flagellated (key difference from Shigella), gram -, non-lactose fermenting bacteria;

 

Invades the colonic mucosa to cause bloody diarrhea;

Responsible for self-limited food an water borne illness; major source is feces- contaminated chicken and beef;

 

Abx may make it worse!

Term
S. typhi
Definition

Salmonella typhi;

Humans are the only host for this bacteirum, which is shed in feces, urine, vomitus, and oral secretions;

 

Causes Typhoid Fever (Rose spots on the abdomen, fever, HA, diarrhea - can remain in the gallbladder of some pts (carriers)

Term
S. enteritides, S. typhimurium
Definition

Salmonella (flagellated, G -, lactose - ) species;

 

Cause self-limited food-water borne gastroenteritis (may be from chicken ingestion)

Term
Typhoid fever 1st week
Definition

Symptoms of S. typhi at this point include: bacteriemia, fever and chills

 

Note that Typhoid fever (caused by S. typhi) is not the same as Typhus (caused by Rickettsia prowazekii (epidemic) or R. typhi (endemic), or in the form of scrub typhis by Rickettsia tasutsugamushi.

Term
Typhoid fever 2nd week
Definition

Symptoms of S. typhi at this point include:

Widespread mononuclear phagocytic involvement with rash, abdominal pain and prostration

Term
Typhoid fever 3rd week
Definition

Symptoms of S. typhi at this point include:

Ulceraiton of peyer patches with intestinal bleeding (remember that salmonella is invasive) and shock.

Term
What areas of the GI tract does Samonella tend to effect?
Definition

Salmonella affects the Ileum and colon, causing Peyer patches to become plateau-like elevations followed by oval ulceration.

It proliferates within macrophages and damages lymphoid tissue.

 

Spleen, liver and gallbladder are involved (remember the gallbladder is the reservoir for carriers)

Term
Salmonella - spread of disease
Definition
Chronic carriers shed the bacteria in their feces, and the gallbladder is the most common reservoir for bacteria and can lead to reinfection
Term
Shigella
Definition

Non-motile, G-, lactose- bacteria;

One of the most common causes of bloody diarrhea; Humans are the only reservoir;

Produces Shiga Toxin;

Low infectious dose (doesn't take many to infect) and large # in stool = highly transmissible via fecal/oral route;

Term
Shigellosis
Definition

A self-limited colitis with diarrhea (bloody), fever, abdominal pain;

 

Shiga toxin it secretes inhbits eukaryotic protein synthesis leading to cell damage and death

Term
Histological features of infection with shigella
Definition

Bacterial infection leads to the following

 

Histo: Mucosa is hemorrhagic and ulcerated, pseudomembranes may be present;

 

Apthous-appearing ulcers may be present, need to differentiate from IBD

Term
Presentaiton of Shigella
Definition

Presents with either

1) watery diarrhea, leading to dysentery with constitutional symptoms persisting for a month, or 

 

2) Subacute presentaiton: waxing and waning diarrhea persisting for several months (need to r/o ulcerative colitis)

Term
Shigellosis
Definition

Manifestation: shorter duration but greater severity in children than in adults, in the subacute presentation may mimic ulcerative colitis.

 

Caused by bacterium with Shiga toxin

Term
Shigellosis - complications
Definition

Complicaitons: uncommon;

Include Reiter Syndrome (reactive arthritis) and hemolytic uremic syndrome (HUS)

Term
Can shigellosis be treated?
Definition

Shigella can be treated with antibiotics which will ↓ the course and ↓ the duration of organism seeding;

 

Do not use antidiarrheal medications as they can prolong symptoms and delay organism clearance;

 

Note that the usefulness of Abx is another key difference between Shigella and Salmonella (abx with salmonella may prolong the duration of infx)

Term
C. Difficile colitis
Definition

Most commonly related to previous abx therapy (especially orally admin abx);

Most common nosocomial related pathogen;

 

Endoscopically: Yellow-white pseudomembranes, patchy distribution, rectum may be spared

Term
C. Difficile colitis - histology
Definition

Intercrypt necrosis and balloned crypts give rise to the laminated pseudomembrane composed of fibrin, mucin, and neutrophils;

Severe and prolonged necrosis may lead to full thickness mucosal necrosis;

Remember: pseudomembranis colitis is not definitively diagnosis for this condition but is highly suggestive

Term
E. coli
Definition

G - rod;

Sx: Bloody diarrhea with severe cramps (watery diarrhea can occur also) mild or no fever;

 

Endoscopically: colonic edema, erosison, ulcers, and hemorrhage;

Right colon is usually more severely affected. Surgery may be necessary to control bleeding or relieve edema-caused obstruciton;

Microthrombi may be seen in small vessels.

Term

This bug may cause HUS or TTP, severe illness in children and elderly.

Think jack in the box and contaminated beef.

Definition
E. coli (especially the O157:H7 serotype)
Term
What organism causes ischemia-like surface atrophy and erosion of the intestines?
Definition
E coli (though remember that most are non-pathogenic (colonize the normal GIT)
Term
ETEC
Definition

Principal cause "Travelers diarrhea";

Spread via contaminated food and water: common in children under 2 years of age;

 

Produces LT and ST toxins which inhibit intestinal absorption and induce chloride and water secretion;

 

Clinical symptoms include: secreteory, noninflammatory diarrhea, dehydration and, in severe cases, shock

Term
EHEC
Definition

Large outbreaks in developed countries have been traced to inadequately cooked contaminated ground beef, vegetables and milk;

Etiology: shiga-like toxin which inhibits protein synthesis: 0157:H7 serotypes most likely to cause bloody diarrhea and HUS*

Term
EIEC
Definition

Similar to Shigella;

Transmitted via food, water and person-to-person contact;

No toxins*;

Invades epithelial cells and causes histologic features of acute self-limited colitis (Invasive necrosis and inflammation, dysentery);

 

Age: young children

Term
EAEC
Definition

Organisms can adhere to epithelial enterocytes via adherence fimbriae;

Dispersin, a bacterial surface protein, neutralizes the negative surface charge of lipopolysaccharide;

 

Produces an enterotoxin, but damage from it is minimal Symptoms: Diarrhea in children and adults

Term
Dispersin
Definition
A bacterial surface protein secreted by EAEC, that neutralizes the negative surface charge of lipopolysaccharide
Term
Parasitic enterocolitis
Definition
Commonly caused by: Ascaris lumbricoides (giant nematode/roundworm), strongyloides (nematode), hookworm, pinworms, amoeba
Term
Nematode enterocolitis
Definition
Enterocolitis caused by ascaris lumbricoides, strongyloides, hookworms, enterobius vermicularis, trichuris trichiuria
Term
Skin entry of parasites
Definition

Strongyloides and hookworms enter and cause parasitic enterocolitis by this mode;

Larvae penetrate the skin of the feet and migrate through the bloodstream, cause intestinal infections;

Term
fecal-oral entry of worms
Definition
Ascaris lumbricoides, enterobius vermicularis, and trichuris trichiura enter via the fecal/oral/ingestion route and cause parasitic enterocolitis by this mode of entry
Term
Cestode enterocolitis
Definition
Cestode = Tapeworm;
Enterocolitis cuased by diphyllobbothrium latum (fish tapeworm), taenia solium (pork tapeworm), hymenolepsis nana (dwarf tapeworm)
Term
Diphyllobothrium latum
Definition

Fish tapeworm (Cestode);

 

Causes B12 deficiency;

Term
Taenia solium
Definition
pork tapeworm (Cestode)
Term
Hymenolepsis nana
Definition
Dwarf tapeworm (Cestode)
Term
Entamoeba histolytica
Definition

Protozoan;

Causes amebiasis by fecal-oral transmission;

Can cause dysentery and liver abscesses;

 

Ingested quadrinucleate cysts colonize in the colon and release trophozoites;

Term
Amebiasis dysentery
Definition
Occurs when amebae attach to colonic epithelium, induce apoptosis, invade crypts and laterally into the lamina propria; inflammation, ,tissue damage and a flask shaped ulcer (undermining ulcer with narrow neck)
Term
What does the presence of a flask-shaped ulcer suggest?
Definition
Protozoal infection (Amebiasis)
Term
Entamoeba histolytica - clinical presentation of infection
Definition

Clinical presentation: Abdominal pain, bloody diarrhea, weight loss;

Acute necrotizing colitis and megacolon may occur - both are associated with increased mortality;

 

Treat with Metronidazole

Term
Metronidazole
Definition

Antibiotic treatment for Entamoeba histolytica;

 

This drug is used to treat amoeba because they are obligate fermenters of glucose - the drug inhibits pyruvate oxidoreductase which is required for fermentation

Term
Entamoeba histolytica - histology and behavior
Definition

Histology: cysts are resistant to stomach acid;

Most frequently found in cecum and ascending colon. Sigmoid, rectum and appendix may be involved;

May penetrate splanchnic vessel and embolize to liver;

 

Abscesses in about 40% of patients (liver), rarely but can spread to lung and heart (directly), or to the brain and kidney (hematogenously.)

Term
Enterobius vermicularis
Definition

Common parasite of the appendix;

Common in ages 5-15;

Worm is found in appendiceal lumen with no mucosal inflammatory response;

Inverse relationship bw this worm and inflammation;

Infects via oral-fecal method;

Does not invade, lives within lumen of the intestine;

Rarely causes serious disease;

Adults worms migrate to the anal opening at night and lay eggs on the peri-rectal tissue. Eggs cause pruritis;

 

Scratching → contamination of hte hands → human-to-human transmission. Worms and eggs are viable outside the body.... reinfection is common;

Term
Infectious acute appendicitis
Definition

Caused by bacteroides fragilis (Frequent anaerobe), E. coli (frequent aerobe), Streptococcus milleri: common aerobe;

 

Linked to 7x ↑ risk of abscess formation

Term
Streptococcus milleri
Definition
infectious cause of acute appendicitis, common aerobe; linked to 7X risk of abscess formation
Term
Bacteroides fragilis
Definition
Most frequent anaerobic cause of acute appendicitis
Term
Escherichia coli
Definition
Most frequent aerobic cause of acute appendicitis
Term
Common variable immunodeficiency
Definition

Most common symptomatic primary immune deficiency, heterogenous clinical and immunologic features;

Patients present at any age;

Pt present with reccurent bacterial infections;

 

Are at risk for chronic inflammatory disorders and malignancies of the GI tract

Term
CVID infections
Definition

Common Variable ImmunoDeficiency;

Small bowel abnormalities may include: villous blunting, ↑ intraepithelial lymphocytes, and nodular lymphoid hyperplasia;

The trophzoite form of the organism can be identified on small bowel biopsy;

 

Common immunodeficiency of the small bowel

Term
Giardia lamblia
Definition

Protozoan, ferments glucose, lacks mitochondria;

2 forms: dormant but infectious cyst (oral-fecal), and trophozoites that multiply in the intestine;

As this bug moves from duodenum to jejunum, ↓ in availablity in cholestrol induces transition from trophozoites into cysts;

These adhere to but do not invade the intestinal epithelial cells;

Causes diarrhea but not dystentery*

Think in cases of watery diarrhea in pts who spend time outdoors!

Term
Giardia lamblia - histo and epi
Definition

MC pathogenic parasite infection in humans*;

 

Histo: ranges from normal SI mucosa to marked blunting of villi with mixed inflammatory infiltrate in lamina propria;

Immunity is limited by the parasite's ability to vary its major surface proteins to antigenicallly distinct forms

Term
Endotoxin causes septic shock by triggering the release of __________________.
Definition
TNF, IL-1, IL-2
Term
Name some examples of host response to infection causing injurious effects.
Definition

HBV damaging liver cells,

TB causes tissue damage when the body attempts to sequester it,

Post-streptococcal GN (IC deposition),

Sepsis

Term
What class of virus is measles?
Definition
Measles (aka Rubeola) is a RNA paramxovirus
Term
What are some complications of measles?
Definition

Subacute, sclerosisng panencephalitis,

Inclusion body encephalitis

Term
The oral lesions of measles are called ____________ .
Definition
Koplik spots
Term
What cells are pathogenomic for measles?
Definition

Warthink-Finkeldy Cells

(Multinucleated giant cells with eosinophilic, nuclear inclusion bodies);

 

Found in the lymphoid organs, lungs and sputum of measles patients.

Term
How does measles effect the lymphoid organs?
Definition
Causes follicular hyperplasia, the formation of large germinal centers and warthin finkledy cells.
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