Gallbladder/Pancreas Key Concepts Flashcards
these stones arise exclusively in the gallbladder, and range from 100% pure (rare) to around 50% cholesterol
- pale yellow, round to ovoid, have a finely granular, hard external surface, which on transection reveals a glistening radiating crystalline palisade (looks like fence posts in a line)
- multiple stones usually present, that range up to several cm in diameter
- stones are radiolucent
cholesterol stones
these stones are brown to black
- black stones found in sterile gallbladder (50-75% are radiopaque due to calcium salts)
- brown stones found in infected large bile ducts, tend to be laminated and soft (may have soap-like or greasy consistency), are radiolucent
pigment stones
gallbladder usually enlarged and tense, may assume a bright red or violet, blotchy to green-black discoloration
- serosa frequently covered by fibrinous exudate that may be fibrinopurulent
acute cholecystitis
an obstructing stone is usually present in the neck of the gallbladder or cystic duct
- gallbladder lumen may contain one or more stones and is filled with a cloudy or turbid bile that may contain large amounts of fibrin, pus, and hemorrhage
calculous cholecystitis
what is it called when gallbladder exudate is virtually pure pus?
- in mild cases, the gallbladder wall is thickened, edematous, and hyperemic
- in more severe cases, is transformed into green-black necrotic organ (gangrenous cholecystitis)
gallbladder empyema
what causes acute “emphysematous” cholecystitis?
the invasion of gas-forming organisms, notable clostridia and colioforms
in this condition, the serosa is usually smooth and glistening, but may be dulled by subserosal fibrosis
- dense fibrous adhesions may remain as sequelae or preexistant acute inflammation
- wall is variably thickened, ad has opaque gray-white appearance
- mucosa itself is generally preserved
- in mild cases: only scattered lymphocytes, plasma cells, and macrophages in the mucosa and subserosal fibrous tissue
- in more severe cases: marked subepithelial and subserosal fibrosis, with mononuclear cell infiltration
subserosal fibrosis
what are Rokitansky-Aschoff sinuses?
buried crypts of epithelium within the gallbladder wall with outpouchings of mucosal epithelium through the wall
extensive calcification within the gallbladder wall, notable for a marked increase
porcelain gallbladder
in this condition, the gallbladder has a massively thickened wall and is shrunken, nodular, and chronically inflamed with foci of necrosis and hemorrhage
- is triggered by rupture of Rokitasky-Aschoff sinuses into the wall of the gallbladder, followed by an accumulation of macrophages that have ingested biliary phospholipids
thogranulomatous cholecystitis
lipid-containing cells with foamy cytoplasm
xanthoma cells
atrophic, chronically dilated gallbladder, may contain only clear secretions
hydrops of the gallbladder
what are the two patterns of growth seen in carcinomas of the gallbladder?
infiltrating and exophytic
this pattern of gallbladder carcinoma is more common and usually appears as a poorly defined area of diffuse mural thickening and induration
- deep ulceration can cause direct penetration into the liver or fistula fistulation to adjacent viscera into which the neoplasm has grown
- scirrhous (slow-growing malignant tumor with very firm consistency)
infiltrating carcinoma
this pattern of carcinoma grows into the lumen as an irregular, cauliflower mass, but at the same time invades the underlying wall
exophytic carcinoma
most carcinomas of the gallbladder are what?
adenocarcinomas
what type of carcinoma generally has a better prognosis than the others?
papillary tumors
what are common sites of metastasis of gallbladder carcinomas?
peritoneum, GI tract, and lungs
it is common to find what, in the epithelium adjacent to invasive cancer, or in gallbladders with long-standing cholelithiasis
- these are nearly always flat dysplasias, with varying grades of cellular atypia, including carcinoma-in-situ
preneoplastic (dysplastic) lesions
what are risk factors for the development of cholesterol stones?
advancing age, female gender, estrogen use, obesity, and heredity
what almost always occurs in association with cholelithiasis?
cholecystitis
- although in about `0% of cases, it occurs in the absence of gallstones
what is a risk factor for gallbladder cancer?
gallstones
NOTE: typically gallbladder cancers are detected late because nonspecific symptoms and hence carry a poor prognosis
what is the most common reason for emergency cholecystectomy?
acute calculous cholecystitis
what is a reversible form of pancreatic parenchymal injury associated with inflammation?
acute pancreatitis
what are the risk factors for acute pancreatitis?
- excessive alcohol intake
- pancreatic duct obstruction
- genetic factors (PRSS1, SPINK1)
- traumatic injuries
- meds
- infection
- metabolic disorders -> hypercalcemia
- ischemia
fibrous, atrophy, dropout of acini, and variable dilation of pancreatic ducts
- the gland is hard, sometimes with visibly dilated ducts containing calcified concretions
- chronic inflammatory infiltrate around lobules and ducts
- ductal epithelium may be atrophied or hyperplastic, or may show squamous metaplasia
- acinar loss
- usually a relative sparing of islets of Langerhans
- when caused by alcohol abuse, ductal dilation and intraluminal protein plugs with calcifications are seen
chronic pancreatitis
duct-centric mixed inflammatory cell infiltrate, venulitis, and increased numbers of IgG4-secreting plasma cells
autoimmune pancreatitis
irreversible injury of the pancreas leading to fibrosis, loss of pancreatic parenchyma, loss of exocrine and endocrine function, and high risk of developing pseudocysts
chronic pancreatitis
what are the most common causes of chronic pancreatitis?
- repeated bouts of acute pancreatitis
- chronic alcohol abuse
- germline mutations in CFTR (CF!), especially when combined with environmental stressors
usually solitary, may be situated within the pancreas, or more commonly in the lesser omental sac or in the retroperitoneum between the stomach and transverse colon or between the stomach and transverse colon, or between stomach and liver (can also be sub-diaphragmatic)
- form when areas of intra-pancreatic hemorrhagic fat necrosis are walled off by fibrous tissue and granulation tissue
pseudocytsts
virtually all serous cystic pancreatic neoplasms are what?
benign
curable noninvasive cystic neoplasms that can progress to incurable invasive carcinoma
intra-ductal papillary mucinous neoplasms
where do approximately 60% of cancers of the pancreas arise?
in the head
- 15% in the body
- 5% in the tail
- 20% diffusely involve the entire gland
the vast majority of pancreatic carcinomas are what?
ductal adenocarcinomas that recapitulate to some degree normal ductal epithelium by forming glands and secreting mucin
what are two characteristic features of pancreatic cancer?
- they are highly invasive (even “early” cancers invade peripancreatic tissue)
- elicits an intense host reaction in the form of dense fibrosis (desmoplastic response)
what do most carcinomas of the head of the pancreas obstruct?
the distal common bile duct
what is the consequence of a blocked common bile duct?
marked distention of the biliary tree in about 50% of patients
- most develop jaundice
what is the difference between carcinoma of the head vs the body and tail of the pancreas?
carcinomas of the body and tail do not impinge on the biliary tract and hence remain silent for some time
- they may be quite large and most are widely disseminated by the time they are discovered
where do pancreatic cancers often grow along and invade?
nerves, and invade into blood vessels and the retroperitoneum
- they can directly invade the spleen, adrenals, transverse colon, and stomach
what lymph nodes are frequently involved in pancreatic cancer?
peripancreatic, gastric, mesenteric, omental, and portohepatic
where does distant metastasis occur in pancreatic cancer?
liver and lungs
moderately to poorly differentiated adenocarcinoma forming abortive tubular structures or cell clusters, show what kind of growth pattern?
aggressive, deeply infiltrative growth pattern
malignant glands are poorly formed and are usually lined by pleomorphic cuboidal-columnar epithelial cells
- what type of pancreatic cancer is the exception to this?
well-differentiated carcinoma
what is the leading preventable cause of pancreatic cancer?
cigarette smoking
what is a pancreatic intraepithelial neoplasia?
well-defined precursor lesion that can give rise to pancreatic cancer
what illicit an intense desmoplastic response?
ductal adenocarcinomas
what are the genes most frequently mutated or otherwise altered in pancreatic cancer?
KRAS, p16/CDKN2A, TP53, SMAD4
how to most patients with pancreatic cancer present clinically?
abdominal pain, weight loss
- sometimes accompanied by jaundice and DVT
- succumb to the disease within 1-2 years
