anus, perotineum, GB, appendix Flashcards
robbins
a normal true diverticulum of the colon
appendix
in what population is acute appendicitis most common
young adults and adolescents,
males
pathogenesis of acute appendicitis
= a progressive increase in intraluminal pressure that compromise venous outflow
overt luminal obstruction with a mass of stool, tumor, mass of worms–> stasis –> bacterial proliferation–> ischemia and inflammation–> edema and neutrophil infiltration into lumen, muscle, and surrounding soft tissue
dull granular erythematous surface of the appendix
acute appendicitis
a dx of acute appendicitis requires ____
neutrophilic infiltration of the muscularis propria
pathogenesis of acute gangrenous appendicitis
compromise of the appendiceal vessels to the extent of large hemorrhaging ulceration and gangrenous necrosis that extends to the serosa
clinical presentation of acute appendicitis
first, periumbilical pain localized to RLQ
then, nausea, vomiting, low grade fever, mild WBC elevation
McBurney sign= tendy 2/3 between umbilicus to ASIS
but often classical signs are not present
complications and prognosis of untreated appendicitis
sign morbidity
perforation pyelophlebitis portal V thrombosis liver abscess bacteremia
most common tumor of the appendix
well differentiated neuroendocrine tumor aka carcinoid tumor
prognosis of a carcinoid tumor of the appendix
usually found incidentally during surgery
almost always benign, can reach up to 2-3 cm
huge bulge at end of appendix but met is rare
_______ may cause obstruction of the appendix and enlargement that mimics acute appendicitis
adenocarcinoma of the appendix
a dilated appendix filled with mucin, _____, can be secondary to an obstruction caused by ____ or a ____/_____
mucocele
inspissated mucin or a cystadenoma/ mucinous cystadenocarcinoma
what is the prognosis of a mucinous cystadenocarcinoma of the appendix
can invade through the appendiceal wall and lead to intraperotineal seeding and swelling
–> pseudomyxoma peritonei = the abdomen fills with tenacious, semisolid mucin –> ultimately fatal
histology breakdown of the anus
top 1/3= columnar rectal epithelium
middle 1/3= transitional epithelium
lower 1/3= stratified squamous epithelium
______ of the anal canal may have typical glandular (~__ 1/3) or squamous (~__ 1/3) patterns of differentiation
carcinomas
upper
lower
in ________ of the anal canal can have the following histological patterns
______ = a differentiation pattern of tumors of the anal canal = populated by immature cells derived from the basal layer of transitional epithelium
or mixed with squamous or mucinous differentiation
anal cell carcinoma
basaloid pattern
pure squamous cell carcinoma of the anal canal is frequently associated with _____, which also causes precursor lesions like ____
HPV
condyloma acuminatum
_______ develop secondary to persistently elevated venous pressure within the hemorrhoid plexus
hemorhoids
most frequent predisposing influences for hemorrhoids
straining at defecation bc of constipation
venous stasis of pregnancy
portal HTN
pathogenesis of hemorrhoids
portal HTN in the rectum,
why are anal varices both less common and less serious than hemorrhoids
because the variceal dilations of the anal and perianal venous plexus form collaterals that connect portal and caval system
differentiate between external and internal hemorrhoids
external: within inferior hemorrhoidal plexus and below the anorectal line
internal= dilation of superior hemorrhoidal plexus and are within the distal rectum
internal no hurt, external hurt
clinical presentation of hemorrhoids
pain and rectal bleeding with bright red blood on tissue
population associated with hemorrhoids
older than 30 and prego
trx for hemorrhoids
not an emergency
sclerotherapy, rubber band ligation, or infrared coag
severe/external can be removed via hemorrhoidectomy
although ____ of the peritoneal cavity are less common than inflammation and infection, they carry a grave prognosis
tumors
most common causes of peritonitis
leakage of bile or pancreatic enzymes
perforation/rupture of biliary system
acute hemorrhagic pancreatitis
fb= surgery, granulomas, fibrous scarring
endometriosis
ruptured dermoid cyst–> release keratins and induce an intense gramulomatous rxn
perforation of abd viscera
leakage of bile or pancreatic enzymes into peritoneal cavity –> ____
sterile peritonitis
perforation/rupture of biliary system –> a highly ____ peritonitis, usually complicated by ______
irritating
bacterial super-infection
link acute hemorrhagic pancreatitis to peritonitis
=leakage of pancreatic enzymes and fat necrosis
can lead to damaged bowel–> bacterial spread
link endometriosis to peritonitis
causes hemorrhage into the cavity, acts as an irritant
most common agents of bacterial peritonitis
E. Coli
S. aureus
enterococci
C. perfringens
spontaneous bacterial peritonitis is seen most often in what population
those with cirrhosis, ascites
also, but less frequently, children with nephrotic syndrome
cellular inflammatory response in peritonitis is composed of what
–> ?
dense collection of neutrophils and fibinopuruent debris that coat the viscera and abd walls
usually superficial
becomes suppurative–> subhepatic and subdiaphragmatic abscesses
dense fibrosis that may extend to involve the mesentry
sclerosing retroperitonitis
etiology of sclerosing retroperitonitis
igG4 related autoimmune ds–> lead to fibrosis of many tissues, OFTEN the ureters
primary malignant tumors arising from peritoneal lining are _____ that are similar to tumors of the ___ and ____
mesothelioma
pleura & pericardium
peritoneal mesothelioma is almost always associated with sign _____
asbestos exposure
while primary tumors of the peritoneum are ____, the most common is _____
rare
desmoplastic small round cell tumor
desmoplastic small round cell tumor- prognosis + population
v aggressive
children and YA
desmoplastic small round cell tumor- etiology
reciprocal translocation of t(11,22) (p13;q12) –> fursion of EWS and WT1 genes
secondary tumors of the peritoneum may involve the peritoneum by spreading/seeing, resulting in __________
peritoneal carcinomatosis.
more than 95% of biliary tract ds is attributable to
cholelithiasis aka gallstones
aberrant location of the gallbladder is most commonly located where
partial/complete embedding in th eliver
most common congenital anomaly of the gall bladder
phrygian cap= a folded fundus
define true biliary atresia
agenesis of all or any portion of the hepatic or common bile ducts and hypoplastic narrowing of the biliary channels
clinical presentation of gallstones
cast majority are silent and most individuals remain pain free for decades
most common types of gall stones
crystalline cholesterol monohydrate
and pigment stones (bilirubin calcium salts)
populations at higher risk for gallstones
US+Western Europe have 90% of stones
75% of Pima Natives, Hopi, and Navajo.
in non-Western= setting of bacterial infections of biliary tree and parasitic infections
most common type of gallstone in the non-western populations specifically
pigment stones
major risk factors for developing gallstones
middle age or older females caucasians for chol, asians for pigment hypersecretion of biliary chol metabolic syndrome and obesity estrogen exposure via OTC/pregnancy rapid weight loss hyperlipidemia
acquired gallbladder stasis
mutations in ABC transporters of biliary lipids in hepatocytes
connect increased estrogen levels to gallstones
increased estrogen–> increased expression of hepatic lipoprotein receptors + HMG-CoA reductase activity–> increased chol uptake and biosynthesis–> increased biliary secretion of chol
x ABCG8 gene –>
higher risk of cholesterol gallstones
etiology of cholesterol gallstones
when [chol] exceeds solubility capacity of bile, chol can no longer remain dispersed and nucleates into solid chol monohydrate crystals
accelerated chol crystal nucleation
hypersecretion of mucus in gall bladder (traps nucleated crystals)
etiology of pigment gallstones
elevated levels of unconjugated bilirubin in bile = chronic hemolytic anemia, severe ileal dysfunction or bypass, bacterial contamination of biliary tree,
infection with E Coli, Ascaris lumbricoides, C sinensis–> increased microbial B-glucoronidase–> increased risk
secondary to Gi ds like ileal ds, ileal resection/bypass/CF w pancreatic insufficiency
what is a pigment gallstone made of
mix of insoluble Ca salts of unconjugated bilirubin + inorganic Ca salts
cholesterol stones exclusively arise where
within the gallbladder
differentiate between appearance of chol and pigment gallstones
chol= pale yellow, round-ovoid, fine granular, hard external surface with glistening radiating crystalline palisade inside
with increased chol can become grey-white to black and are radioluscent
pigment= brown-black. brown in sterile bile and brown in infected bile. made of unconj bilirunin, CaCarbonate, CaPO4, mucin glycoprotein and some chol crystals. speculated contour
clinical presentation of the 4% of gallstones that actually become symptomatic
biliary colic= excruciating, constant pain following a fatty meal. localized to RUQ or epigastrium that may radiate to the R shoulder or back.
pain with cholecystitis secondary to cholelithiasis
severe complications= empyema, perforation, fistulas, cholangitis, obstructive cholestasis, pancreatitis
(GB) the larger the calculi, the less likely they are to _____, and so they are less ____ though occasionally a large stone might cause ____ obstruction
enter the cystic or common ducts to produce obstruction
dangerous
intestinal by eroding directly into the adjacent loop of SB
90% of acute calculous cholecystitis is precipitated by
obstruction of the neck or cystic duct by a stone
most common reason for emergency cholecystectomy
acute cholecystitis
cholecystitis without gallstones may occur in ______
severely ill patients
etiology of acute cholecystitis
result from chemical irritation and inflammation of gallbadder post obstruction of stones
mucosal phospholipases hydrolyze luminal lecithin to toxic lysolecithins–> glycoprotein mucus layer is disrupted, exposing the mucosal epithelium to the direct detergent action of bile salts
prostglandins released from the wall contribute to inflammation, distention and increased intraluminal P–> x blood flow to the mucosa
only later will bacterial contamination develop
acute calculous cholecystitis frequently develops in ______ who have symptomatic gallstones
diabetic pts
acute Acalculous cholecystitis is thought to result from
ischemia
cystic A is an end artery
also other things obstructing the cystic duct that aren’t stones
risk factors for acute Acalculous cholecystitis
- sepsis with hypotension and multi-system organ failure
- immunosupression
- major trauma and burns
- DM
- infections
gall bladder is enlarged, tense, bright red or blotchy, violet to green-black discoloration, imparted by subserosal hemorrhages: covered by fibrinous exudate
acute cholecystitis
calculous cholecystitis, usually present where
neck of the gallbladder or cystic duct
define gallbladder empyema
when the exudate found within the gallbladder lumen is virtually pure pus, as opposed to fibrin+pus+hemorrhage
green-black necrotic gallbladder with perforations
gangrenous cholecystitis
gallbladder invasion by clostridia and coliforms=
acute “emphysematous cholecystitis”
clinical presentation of acute calculous cholecystitis
usually have had episodes of pain before
an episode beings with progressive RUQ/epigastric pain lasting more than 6 hours
associated with fever, anorexia, tachy, sweating, nausea, and vomiting
hyperbilirubinemia, leukocytosis with mild elevations of serum alkaline phosphate values
can be super mild and resolve on its own or might be a surgical emergency
clinical presentations of acute Acalculous cholecystitis
insidious, since sx are obstructed by the underlying conditions precipitating the attacks
in the case of severely ill patients, early recognition of acute Acalculous cholecystitis is crucial or else…
almost ensured a fatal outcome
incidence of ____ and ____ are a lot higher in Acalculous than calculous cholecystitis
gangrene and perforation
what agents can, albeit rarely, give rise to acute Acalculous cholecystitis
salmonella typhi
staphylococci
a more indolent form of acute acalculous cholecystitis can occur in what patient populations + settings
systemic vasculitis
severe atherosclerotic ischemic ds in the elderly
AIDS
biliary tract infections
chronic cholecystitis can be a sequel to __________, but in many instances it develops in apparent absence of ________
repeated bouts of mild to severe acute cholecystitis
antecedent attacks
chronic cholecystitis is associated with ____ 90% of the time
cholelithiasis
organisms associated with chronic cholecystitis
E. Coli
enterococci
morphological changes with cholecystitis
subserosal fibrosis, wall thickness, inflammation to variable amounts
Rokitansky-Aschoff sinuses= buried crypts of epithelium within the gallbladder wall
porcelain gallbladder= extensive dystrophic calcification of the GB wall
what is xanthogranulomatous cholecystitis
GB is chronically inflamed with foci of necrosis and hemorrhage
triggered by rupture of Rokitansky-Aschoff sinuses into the wall of the gall bladder followed by an accumulation of Mø that have ingested biliary phospholipids
define hydrops of the gallbladder
atrophic, chronically obstructed GB that is often dilated, and can contain clear secretions
clinical presentation of chronic cholecystitis
recurrent attacks of steady epigastric/RUQ pain
N/V, intolerance of fatty foods
complications of acute/chronic cholecystitis
- bacterial super-infection–> cholangitis/sepsis
- GB perforation and local abscess formation
- GB rupture with diffuse peritonitis
- biliary enteric fistula, w drainage of bile into adjacent organs, entry of air and bacteria into the biliary tree, and potentially gallstone-induced ileus
- aggravation of comorbid ds
- porcelain gallbladder
_____ is the most common malignancy of the extrahepatic biliary tract
carcinoma of the gallbladder
what populations have the highest rates of carcinoma of the gallbladder
chile, bolivia, north indians, Natives/Hispanics in the southwest US
women
prognosis of carcinoma of the gallbladder
less than 10% 5 year survival
most are diagnosed at an advanced stage,
most important risk factors for carcinoma of the gallbladder
gender
ethnicity
presence of gallstones –> chronic inflammation
genetic mutations associated with carcinoma of the gallbladder
oncoprotein ERBB2 (Her-2/neu) overexpression
chromatin remodelling, PBRM1 and MLL3
carcinoma of the gallbladder- 2 growth patterns
infiltrating = most common
-poorly defined area of diffuse mural thickening and induration, firm and scirrhous, can ulcerate into liver/other surrounding viscera
exophytic= irregular, cauliflower mass
-invades the underlying wall
most carcinomas of the gallbladder are
adenocarcinomas
papillary tumors of the GB have a ____ prognosis than other tumors of the GB
better
prognosis of GB carcinoma
by the time they are discovered, most have invaded the liver, and many have extended to the cystic duct/adj bile ducts/portal-hepatic LNs
common sites of GB carcinoma seeding
peritoneum
GI tract
lungs
lesions in the epithelium in a gallbladder with long-standing cholelithiasis, nearly always flat with varying grades of cellular atypia
preneoplastic lesions, often carcinoma-in-situ
uncommon to find
clinical presentation of carcinoma of the gallbladder
usually insidious, uncommon to diagnose pre-op
present with abd pain, jaundice, anorexia, N/V
early detect in pts with a palpable GB and acute cholecystitis
trx for carcinoma of the gallbladder
surgical resection, chemo
