Liver Path Flashcards
acute liver failure usually displays what type of necrosis?
massive hepatic necrosis
broad regions of parenchymal loss surrounding islands of regenerating hepatocytes
- liver is small and shrunken
hepatic necrosis
acetaminophen overdose causes what kind of necrosis?
hepatocellular necrosis
diffuse poisoning of liver cells without obvious cell death and parenchymal collapse
- related to fatty liver of pregnancy or idiosyncratic reactions to toxins
- usually related to mitochondrial dysfunction (hepatocytes are unable to perform usual metabolic function)
diffuse microvesicular steatosis
regenerating parenchymal nodules surrounded by dense bands of scar and variable degrees of vascular shunting
cirrhosis
- there is no single cirrhosis, but many cirrhoses
what is a new, important classification for assessing the presence and degree of portal HTN?
Child-Pugh classification
biopsy specimens demonstrate narrow, densely compacted fibrous septa separated by large islands of intact hepatic parenchyma are less likely to have what?
portal hypertension
biopsy specimens demonstrating broad bands of dense scar, often with dilated lymphatic spaces, with less intervening parenchyma are likely to be progressing toward what?
portal hypertension -> end stage disease
in chronic liver disease, what increases with advancing stage of disease?
ductular reactions
liver stem cells in parenchymal regeneration increase as the preexisting hepatocytes undergo replicative senescence after years to decades of high turnover
- these reactions may incite some of the scarring in chronic liver disease and thus may have a negative effect on progressive liver disease
ductular reactions
what can happen (although rarely) in fully established cirrhosis?
regression of fibrosis
- with increasing numbers of effective treatment for cirrhosis-causing conditions, we now understand that regression of scars can take place
- all cirrhotic livers show elements of both progression and regression
what type of portal hypertension?
- obstructive thrombosis of portal vein
- structural abnormalities such as narrowing of the portal vein before it ramifies in the liver
prehepatic causes
what type of portal hypertension?
- cirrhosis
- nodular regenerative hyperplasia
- primary biliary cirrhosis
- schistosomiasis
- massive fatty change
intrahepatic causes
what type of portal hypertension?
- severe right-sided heart failure
- constrictive pericarditis
- hepatic vein outflow obstruction
posthepatic causes
what is the mnemonic for causes of acute liver failure?
A: acetaminophen, hep A, autoimmune hepatitis
B: hep B
C: hep C, cryptogenic
D: drugs/toxins, hep D
E: hep E, esoteric causes (Wilson disease, Budd-Chiari)
F: fatty change of microvesicular type (fatty liver of pregnancy, valporate, tetracycline, Reye syndrome)
which hepatitis virus?
- ssRNA
- hepatovirus family
- fecal-oral transmission
- no progression to chronic
- 2-6 week incubation
- dx by detection of serum IgM Ab
Hep A
which hepatitis virus?
- partially dsDNA
- hepadnavirus family
- parenteral, sexual contact, perinatal transmission
- 2-26 week incubation
- 5-10% progresses to chronic
- detection of HBsAg or Ab to HBcAg, PCR for HBV DNA
Hep B
which hepatitis virus?
- ssRNA
- flavivirdae family
- parenteral, intranasal cocaine
- 4-26 week incubation
- > 80% progression to chronic
- dx by 3rd generation ELISA for Ab detection, PCR for HCV RNA
Hep C
which hepatitis virus?
- circular defective ssRNA
- subviral particle in deltavirdae family
- parenteral transmission
- 2-26 weeks incubation
- 10% (coinfection), 90% for superinfection
- detection of IgM and IgG Ab, HDV RNA serum, HDAg in liver
Hep D
which hepatitis virus?
- ssRNA
- hepevirus family
- fecal-oral transmission
- 4-5 weeks incubation
- progresses to chronic only in immunocompromised hosts
- detection of serum IgM and IgG Ab, PCR for HEV RNA
Hep E
on gross inspection, liver appears normal or slightly mottled
- both acute and chronic infection evoke lymphoplasmacytic (mononuclear) infiltrate
- portal inflammation is minimal or absent
- most parenchymal injury is scattered throughout the hepatic lobule as “spotty necrosis”
acute viral hepatitis
cytoplasm appears empty with only scattered wisps of cytoplasmic remnants
- eventually there is rupture of cell membranes leading to “dropout” of hepatocytes, leaving collapsed sinusoidal collagen reticulin framework behind
hepatocellular necrosis
hepatocytes shrink, becoming intensely eosinophilic, and their nuclei become pyknotic and fragmented
- effector T cells may be present in the immediate vicinity
hepatocellular apoptosis
confluet necrosis of hepatocytes is seen around central veins
- may be cellular debris, collapsed reticulin fibers, congestion/hemorrhage and variable inflammation
- with increasing severity there is central-portal bridging necrosis, followed by parenchymal collapse
severe acute hepatitis
in which hepatitis infection would you see the mononuclear infiltrate especially rich in plasma cells?
Hep A
what is the defining histologic feature of chronic viral hepatitis?
mononuclear portal infiltration
what is the hallmark of progressive chronic liver damage?
scarring
in parallel with increasing scarring there is also increasing ductular reaction, reflecting stem cell activation
- in the most severe cases, continued scarring and nodule formation leads to the development of cirrhosis
progressive chronic liver damage
clinical assessment of chronic hepatitis often requires what two things?
liver biopsy and serologic data
which hepatitis has “ground glass hepatocytes” - cells with endoplasmic reticulum swollen by HBsAg
Hep B
- immunohisto staining can confirm the presence of viral antigen
which hepatitis shows lymphoid aggregates or fully formed lymphoid follicles
- genotype 3 often shows fatty change of scattered hepatocytes, although the infection may also cause systemic alterations leading to metabolic syndrome and therefore, a superimposed non-alcoholic fatty liver disease
Hep C
which hepatitis can have a prominent bile duct injury, that mimics primary biliary cirrhosis?
Hep C
which types never cause chronic hepatitis, only acute?
the vowels: A and E
which types have the potential to cause chronic disease?
the consonants: B, C, D
which type can be transmitted by blood, birthing, and boning?
Hep B
which virus is the most often chronic?
Hep C: 80% will develop chronic hepatitis, 20% of whom will develop cirrhosis
the delta agent, is a defective virus, requiring Hep B co-infection for its own capacity to infect and replicate
Hep D
this virus is endemic in equatorial regions and frequently epidemic
Hep E
what are the main inflammatory cells in both acute and chronic viral hepatitis?
T cells
patients with long-standing HBV or HCV related cirrhosis are at increased risk for the development of what?
hepatocellular carcinoma
what infection does fibrosis typically follow many years of slowly accumulating parenchymal injury?
viral hepatitis
in this disease, there is an early phase of severe parenchymal destruction followed rapidly by scarring
- severe necroinflammatory activity indicated by extensive interface hepatitis or foci of confluent/parenchymal collapse
- plasma cell predominance in mononuclear inflammatory infiltrates
- hepatocyte “rosettes”
autoimmune hepatitis
the disease may be rapidly progressive or indolent, both giving rise eventually to liver failure
- very severe hepatocyte injury with widespread confluent necrosis, but little scarring (often seen as symptomatic acute hepatitis and represents the first sign of disease)
- mix of marked inflammation and some degree of scarring, seen in early or later stage disease
- burned-out cirrhosis, with little necroinflammatory activity
autoimmune hepatitis
what type of autoimmune hepatitis is most often seen in middle-aged women and is most characteristically associated with antinuclear and anti-smooth muscle Abs (ANA and ASMA)?
Type 1
what type of autoimmune hepatitis is most often seen in children or teenagers and is associated with anti-liver kidney microsomal autoantibodies (anti-LKM1)?
Type 2
what cell type is the characteristic component of the inflammatory infiltrate in biopsy specimens showing autoimmune hepatitis?
plasma cells
bland hepatocellular cholestasis, without inflammation
cholestatic
- ex: contraceptive and anabolic steroids, antibiotics, HAART
cholestasis with lobular necroinflammatory activity, may show bile duct destruction
cholestatic hepatitis
- associated agents: antibiotics, phenothiazines, statins
spotty hepatocyte necrosis, massive necrosis, chronic hepatitis
hepatocellular necrosis
- associated agents: methyldopa, phenytoin, acetaminophen, halothane, isoniazid
large and small droplet fat, “microvesicular steatosis”, steatohepatitis with Mallory-Denk bodies
fatty liver disease
- assoc agents: ethanol , corticosteroids, methotrexate, total parenteral nutrition
- microvesicular steatosis: valporate, tetracycline, aspirin, HAART
- steatohepatitis: ethanol, amiodarone
periportal and pericellular fibrosis
fibrosis and cirrhosis
- associated agents: alcohol, methotrexate, enalapril, vitamin A
noncaseating epithelioid granulomas
- fibrin ring granulomas
granulomas
- associated agents: sulfonamides, amiodarone, isoniazid
- fibrin ring: allopurinol
what are the associated agents of sinusoidal hepatic obstruction syndrome?
high dose chemotherapy, bush teas
what are the associated agents of Budd-Chiari syndrome?
oral contraceptives
what are the associated agents of Peliosis hepatis?
- blood filled cavities, not lined by endothelial cells
anabolic steroids, tamoxifen
what are the associated agents of Hepatocellular adenoma?
oral contraceptives, anabolic steroids
what are the associated agents of hepatocellular carcinoma?
alcohol, thorotrast
what is the associated agent of cholangiocarcinoma?
thorotrast
what are the associated agents of angiosarcoma?
thorotrast, vinyl chloride
what is the most common hepatotoxin causing acute liver failure?
acetaminophen
what is the most common hepatotoxin causing chronic liver disease?
alcohol
in what acinus zone do all changes in alcoholic liver disease begin?
zone 3, and extend outward toward the portal tracts with increasing severity of injury
lipid droplets accumulate in hepatocytes increasing with amount and chronicity of alcohol intake
- the lipid begins as small droplets that coalesce into large droplets which distend the hepatocyte and push the nucleus aside
- macroscopically, the liver is large, soft, yellow and greasy
hepatic steatosis (fatty liver)
fatty change is completely reversible is there is abstinence from what?
further intake of alcohol
single or scattered foci of cells undergo swelling (ballooning) and necrosis
- swelling results from the accumulation of fat and water, as well as proteins that are normally exported
hepatocyte swelling and necrosis
clumped, amorphous eosinophilic material in ballooned hepatocytes
- made up of intermediate filaments such as keratins 8 and 18 in complex with other proteins such as ubiquitin
- these inclusions are a characteristic, but not specific feature of alcoholic liver disease
Mallory-Denk bodies
neutrophils permeate the hepatic lobule and accumulate around degenerating hepatocytes, particularly those having Mallory-Denk bodies
- may be more or less mixed with mononuclear cells
neutrophilic reaction
what are the 3 characteristics of alcoholic (steato-) hepatitis?
- hepatocyte swelling and necrosis
- Mallory-Denk bodies
- neutrophilic reaction
alcoholic hepatitis often accompanied by prominent activation of sinusoidal stellate cells and portal fibroblasts -> fibrosis, beginning with sclerosis of central veins
- perisinusoidal scar then accumulates in the space of Disse of the centrilobular region, spreading outward, encircling individual or small clusters of hepatocytes in a chicken-wire fence pattern
alcoholic steatofibrosis
when alcohol use continues without interruption over the long term, the continual subdivision of established nodules by new webs of scarring leads to what?
classic micronodular Laennec cirrhosis
chronic disease that can give rise to steatosis, alcoholic hepatitis, progressive steatofibrosis and marked derangement of vascular perfusion leading eventually to cirrhosis
alcoholic liver disease
what is considered to be the consumption threshold for development of alcoholic liver disease?
80 gm/day
the multiple pathologic effects of alcohol include changes in what?
- lipid metabolism
- decreased export of lipoproteins
- cell injury caused by reactive oxygen species and cytokines
what defines pathologic steatosis?
involving more than 5% of hepatocytes
small, medium and large droplets of fat (mostly triglycerides), accumulate within hepatocytes
steatosis
what pathologic process almost completely overlaps in its histologic features with alcoholic hepatitis?
Non-alcoholic fatty liver disease (NAFLD/NASH)
compared with alcoholic hepatitis, mononuclear cells may be more prominent than neutrophils, and Mallory-Denk bodies are often less prominent
- steatofibrosis shows precisely the same features and progression as alcoholic fatty liver disease, although portal fibrosis may be more prominent
- cirrhosis may develop, is often subclinical for years, and when established, steatosis or steatohepatitis may be reduced or absent
NASH
more than 90% of previously described “cryptogenic cirrhosis” is now thought to represent what?
“burned out” NASH/NAFLD
more diffuse steatosis, portal rather than central fibrosis, portal and parenchymal mononuclear infiltration, rather than parenchymal neutrophils
pediatric NASH
what is the most common metabolic disorder?
NAFLD
what is NAFLD associated with?
metabolic syndrome, obesity, T2DM, or other impairments of insulin responsiveness, dyslipidemia and HTN
what is being increasingly recognized as the obesity epidemic spreads to pediatric age groups, even though its histologic features differ somewhat from that seen in adults
pediatric NAFLD
- mutations of genes encoding HFE, transferrin receptor 2, or hepcidin
- mutations of genes encoding HJV (hemojuvelin: juvenile hemochromatosis) neonatal hemochromatosis
hereditary hemochromatosis
- deposition of hemosiderin in the liver, pancreas, myocardium, pituitary gland, adrenal gland, thyroid and parathyroid, joints and skin
- cirrhosis
- pancreatic fibrosis
severe hemochromatosis
in the liver, what compound becomes evident first as golden-yellow hemosiderin granules in the cytoplasm of periportal hepatocytes that stain with Prussian blue
- progressive involvement of the rest of the lobule, along with bile duct epithelium and Kupffer cell pigmentation
iron
- liver parenchyma in later stages is often dark brown to nearly black due to overwhelming iron accumulation
what hepatic iron concentration is associated with development of fibrosis and cirrhosis?
excess of 22,000 ug per gram dry weight
this organ becomes intensely pigmented in hemochromatosis, and may exhibit parenchymal atrophy
- hemosiderin is found in both the acinar and islet cells, and sometimes in the interstitial fibrous stroma
pancreas
this organ is often enlarged in hemochromatosis, and hemosiderin ganules produce a striking brown coloration
- interstitial fibrosis may appear
heart
what does most of the skin pigmentation result from in hemochromatosis?
increased epidermal melanin production
- is also partially attributable to hemosiderin deposition in dermal macrophages
what may develop with deposition of hemosiderin in synovial joint linings?
acute synovitis
excessive deposition of calcium pyrophosphate damages the articular cartilage, producing a disabling polyarthritis referred to as what?
pseudogout
the liver often bears the brunt of injury in this disease, but it may also present as a neurologic disorder
- hepatic changes are variable, ranging from relatively minor to massive damage, and may mimic many other disease processes
- steatosis may be mild-moderate with focal hepatocyte necrosis
- chronic hepatitis in the disease exhibits moderate-severe inflammation and hepatocyte necrosis, mixed with fatty change and features of steatohepatitis
Wilson disease
- excess copper deposition can be demonstrated by special stains (rhodamine stain, orcein stain) but histology isn’t enough to distinguish Wilson disease from viral and drug induced hepatitis
toxic injury to the brain in Wilson disease primarily affects the putamen (of the basal ganglia), which shows atrophy and even cavitation
- what are the eye lesions that develops in patients with neurologic involvement?
Kayser-Fleischer rings
- green to brown deposits of copper is Descemet membrane in the limbus of the cornea
this disease is characterized by the presence of round-over cytoplasmic globules in hepatocytes, which on routine h&e stains are acidophilic, but are strongly periodic, PAS-positive, and diastase-resistant
- globules also present, but diminished in size and number in the PiMZ and PiSZ genotypes
alpha 1 AT deficiency
what may be present as a tip-off to the possibility of a1AT deficiency, if diagnostic globules are absent in young infants?
steatosis
what disease is caused by a mutation in the HFE gene, whose product is involved in intestinal iron uptake by its effect on hepcidin levels
- characterized by accumulation of iron in the liver and pancreas
hereditary hemchromatosis
what disease is caused by a mutation in the metal iron transporters ATP7B, which results in accumulation of copper in the liver, brain (particularly basal ganglia) and eyes (Kayser-Fleisher rings)
Wilson disease
what disease is caused by protein misfolding disorder?
which variant is most likely to impair secretion by hepatocytes and cause disease, particularly when homozygous (PiZZ genotype) results in pulmonary emphysema caused by increased elastase activity and liver injury
a1AT deficiency
accumulation of bile pigment within the hepatic parenchyma
- elongated green-brown plugs of bile are visible in dilated bile canaliculi
- rupture of canaliculi leads to extravasation of bile, which is phagocytosed by Kupffer cells
- droplets of bile also accumulate within hepatocytes, which take on a fine, foamy appearance “feathery degeneration”
cholestasis
distention of upstream bile ducts
- bile ductules proliferate at the portal parenchymal interface, accompanied by stromal edema and infiltrating neutrophils
- labyrinthine ductules reabsorb secreted bile salts, and protect the downstream obstructed bile ducts from their toxic detergent action
acute biliary obstruction
what is the histologic hallmark of ascending cholangitis?
the influx of peri-ductular neutrophils directly into the bile duct epithelium and lumen
what leads to hepatic scarring and nodule formation, generating secondary/obstructive biliary cirrhosis?
inflammation resulting from chronic biliary obstruction and ductular reactions initiating peri-portal fibrosis
what may be superimposed on chronic liver failure, sometimes triggering acute-on-chronic liver failure?
ascending cholanditis
pigmented calcium bilirubinate stones in distended intrahepatic ducts
- the ducts show chronic inflammation, mural fibrosis and peribiliary gland hyperplasia, all in the absence of extrahepatic duct obstruction
hepatolithiasis
lobular disarray with focal liver cell apoptosis and necrosis
- pan-lobular giant cell transformation of hepatocytes, prominent hepatocellular and canalicular cholestasis
- milf mononuclear infiltration of the portal areas
- reactive changes in Kupffer cells
- extramedullary hematopoiesis
neonatal hepatitis
what would make distinguishing neonatal hepatitis from obstructive biliary atresia difficult?
if the parenchymal pattern of injury blends with a ductal pattern of injury, with ductular reaction and fibrosis of portal tracts
inflammation and fibrosing stricture of the hepatic or common bile ducts
- in some individuals this progresses into the intra-hepatic bile ducts, leading to progressive destruction of the intrahepatic biliary tree
biliary atresia
when would biliary atresia be considered surgically correctable?
when the disease is limited to the common duct (type 1) or right and left hepatic bile ducts (type 2)
- known as the Kasai procedure
when is biliary atresia not surgically correctable?
type 3 biliary atresia (90%) of cases, when there is obstruction of bile ducts at or above the porta hepatis
- these cases are not correctable since there are no patent bile ducts amenable to surgical anastomosis
- median age 50
- 90% female
- progressive course
- assoc w/ Sjogren, scleroderma, thyroid disease
- 95% AMA-positive, 50% ANA-positive, 40% ANCA-pos
- normal radiology
- florid duct lesions and loss of small ducts only
primary biliary cirrhosis
- median age 30
- 70% male
- unpredictable, but progressive course
- assoc w/ IBD, pancreatitis, ideopathic fibrosing diseases
- 65% ANCA-positive, 6% ANA-positive, 0-5% AMA-pos
- strictures and beading of large bile ducts, pruning of smaller ducts
- inflammatory destruction of extrahepatic and large intrahepatic ducts
primary sclerosing cholangitis
interlobular bile ducts are actively destroyed by lymphoplasmacytic inflammation with or without granulomas (the florid duct lesion)
primary biliary cirrhosis (PBC)
this disease is quite patchy in distribution
- it is common to see a single bile duct under immune attack in one level of a biopsy specimen, which deeper levels remain unaffected
- ductular reactions follow duct injury and these in turn participate in the development of portal-portal septal fibrosis
PBC
increasingly widespread duct loss, slowly leading to cirrhosis and in end stages, profound cholestasis
- bile accumulation in not centrilobular, unlike in drug-induced or sepsis-assoc cholestasis, but is peri-portal/peri-septal
- it is associated with a feathery degeneration and ballooned, bile stained hepatocytes, often with prominent Mallory-Denk bodies
PBC
what is alternatively seen when patients develop prominent portal hypertension rather than severe cholestasis?
widespread nodularity without the surrounding scar tissue seen in cirrhosis - a feature called nodular regenerative hyperplasia
what is a distinguishing factor of PBC, that separates it from the shrunken, end-stage cirrhotic livers of chronic hepatitis?
in PBC, there is little hepatocyte loss and often regenerative hyperplasia = marked hepatomegaly
impaired bile flow, leading to accumulation of bile pigment in the hepatic parenchyma
- causes include mechanical or inflammatory obstruction, or destruction of the bile ducts or by metabolic defects in hepatocyte bile secretion
cholestasis
most commonly associated with gallstones and malignancies involving the head of the pancreas
- chronic obstruction can lead to cirrhosis
- ascending cholangitis may develop
large bile duct obstruction
may arise through direct effects of intrahepatic bacterial infection, ischemia relating to hypotension caused by sepsis, or in response o circulating microbial products
cholestasis in sepsis
disorder of intra-hepatic gallstone formation, most common in East Asia, that leads to repeated bouts of ascending cholangitis and inflammatory prenchymal destruction
- predisposes to cholangiocarcinoma
primary heptolithiasis
not a specific entitiy, but is variously associated with colangiopathies such as biliary atresia and a variety of other disorders causing conjugated hyperbilirubinemia in the neonate, collectuvely referred to as neonatal hepatitis
neonatal cholestasis
autoimmune disease with progressive, inflammatory, often granulomatous destruction of small-medium sized intrahepatic bile ducts
- occurs most often in women, is associated with other autoantibodies and other autoimmune diseases
primary biliary cirrhosis
autoimmune disease with progressive inflammatory and sclerosing destruction of bile ducts of all sizes, intra and extra-hepatic
- dx made by radiologic imaging of the biliary tree
- occurs most often in younger men and has strong associations with IBD (UC)
primary sclerosing cholangitis
similar to inflammation seen in UC, acute, neutrophilic infiltration of the epithelium superimposed on a chronic inflammatory background
- inflamed areas develop strictures because edema and inflammation marrows the lumen or because of subsequent scarring
large duct inflammation
little inflammation, but show a striking onion skin fibrosis around an increasingly atrophic duct lumen, eventually leading to obliteration by a “tombstone” scare
- dx depends on radiologic imaging of extra and intra-hepatic ducts
- as the disease progresses, the liver becomes markedly cholestatic, culminating in biliary cirrhosis much like that seen with chronic obstruction and primary biliary cirrhosis
small duct inflammation
liver is swollen and red-purple, with a tense capsule
- may be differential areas of hemorrhagic collapse alternating with areas of preserved or regenerating parenchyma (patterns are dependent on which small and large hepatic veins are obstructed)
- microscopically, affected hepatic parenchyma reveals severe centrilobular congestion and necrosis (or fibrosis)
- major veins may contain totally occlusive fresh thrombi, subtotal occlusion, or in chronic cases, organized adherent thrombi
Budd-Chiari syndrome
obliteration of the terminal hepatic venules by subendothelial swelling and collagen deposition
- in acute disease, there is centri-lobular congestion, hepatocellular necrosis, and accumulation of hemosiderin-laden macrophages
- as the disease progresses, obliteration of the lumen of the venule is easily identified with special stains for connective tissue
- in chronic or healed sinusoidal obstruction syndrome, fibrous obliteration of the venule may follow
sinusoidal obstruction syndrome
passive congestion
- liver is slightly enlarged, tense, and cyanotic with rounded edges
- microscopically, there is congestion of centrilobular sinusoids
- with time, centrilobular hepatocytes become atrophic, resulting in markedly attenuated liver cell plates
right-sided cardiac decompensation
hepatic hypoperfusion and hypoxia, causing ischemic coagulative necrosis of hepatocytes in the central region of the lobule (centrilobular necrosis)
- in most instances, the only clinical evidence of centrilobular necrosis or its variants is transient elevation of serum aminotransferases, but the parenchymal damage may be sufficient to induce mild to moderate jaundice
left-sided cardiac failure
the combination of hypoperfusion and retrograde congestion act synergistically to cause what?
centrilobular hemorrhagic necrosis
the liver takes on a variegated mottled appearence, reflecting hemorrhage and necrosis in the centrilobular regions
nutmeg liver
microscopically, there is a sharp demarcation of viable periportal and necrotic or atrophic pericentral hepatocytes, with suffusion (slow spread) of blood through the centrilobular region
passive congestion
sustained, chronic severe congestive heart failure causes what?
- centrilobular fibrosis, sometimes with central-central linking fibrous septa
cardiac sclerosis
10-50 days after hematopoietic stem cell transplantation
- donor lymphocytes attack the epithelial cells of the liver
- results in hepatitis with necrosis of hepatocytes and bile duct epithelial cells, and inflammation of parenchyma and portal tracts
acute graft-versus-host disease
portal tract inflammation, selective bile duct destruction and eventual fibrosis
- portal vein and hepatic vein radicles may show endothelitis with subendothelial lymphocytes lifting the endothelium from it’s basement membrane
- cholestasis may be observed in both acute and chronic graft-versus host disease
chronic graft-versus host disease
infiltration of a mixed portal inflammatory infiltrate associated with bile duct injury and endothelitis
acute cellular rejection
obliterative arteriopathy of small and large arteries leads to ischemic changes in the liver parenchyma
- includes destruction of bile ducts both by immunologic attack and interruption of blood flow
chronic rejection
- can result in vanishing bile duct syndrome, which often required retransplantation
periportal sinusoids contain fibrin deposits associated with hemorrhage into the space of Disse, leading to periportal hepatocellular coagulative necrosis
- blood under pressure may coalesce and expand to form a hepatic hematoma
- dissection of blood under Glisson capsule may lead to catastrophic hepatic rupture
preeclampsia
when do patients with preeclampsia show modest to severe elevation of serum aminotransferases and mild elevation of serum bilirubin
patients with hepatic involvement
diagnosis rests on biopsy identification of the characteristic diffuse microvesicular steatosis of hepatocytes
- in severe cases there may be lobular disarray with hepatocyte dropout, reticulin collapse, and portal tract inflammation, making distinction from viral hepatitis difficult
acute fatty liver of pregnancy
appears as well-demarcated but poorly encapsulated nodule, ranging up to many centimeters in diameter
- presents as a spontaneous mass lesion in an otherwise normal liver, most frequently in young to middle-aged adults
- lesion is generally lighter than the surrounding liver and is sometimes yellow indicating steatosis
- typically there is a central gray-white, depressed stellate scar from which fibrous septa radiate to the periphery
focal nodular hyperplasia
central scar contains large vessels, usually arterial, that typically show fibromuscular hyperplasia with eccentric or concentric narrowing of the lumen
- radiating septa show variable ductular reactions along septal margins
- parenchya between septa is comprised of normal hepatocytes separated by thickened sinusoidal plates
focal nodular hyperplasia
a liver entirely transformed into nodules - grossly similar to micronodular cirrhosis, but without fibrosis
- microscopically, plump hepatocytes are surrounded by rims of atrophic hepatocytes
Nodular regenerative hyperplasia
what can nodular regenerative hyperplasia lead to?
portal HTN
- occurs in association with conditions affecting intrahepatic blood flow, including solid-organ (esp renal) transplantation, hematopoietic stem cell transplantation, and vasculitis
- also occurs in HIV patients in association with rheumatologic diseases
tumors resulting from HNF1-a mutations, are often fatty and devoid of cellular or architectural atypia
- they have almost no risk of malignant transformation
- liver fatty acid binding protein (LFABP), a downstream regulated protein of HNF1-a, is expressed in all normal hepatocytes, but is absent in these tumors due to the inactivating mutation of HNF1-a -> thus immunostaining for LFABP showing it’s absence is diagnostic of the mutation
hepatocellular adenoma
high degree of cytologic or architectural dysplasia or even overt areas of hepatocellular carcinoma
- immunostain usually shows nuclear translocation indicative of its activated state this change is diagnostic
- glumatine synthetase,is also diffusely positive in these tumors
b-catenin mutated hepatocellular adenomas
unlike other hepatocellular adenomas, which are comprised of only hepatocytes and vessels with minor amounts of stroma, these lesions characteristically have areas of fibrotic stroma, mononuclear inflammation, ductular reactions, dilated sinusoids, and telangiectatic (dilated small venules)
- these tumors overexpress acute phase reactants such as C-reactive protein and serum amyloid A
inflammatory hepatocellular adenoma
scattered hepatocytes, usually near portal tracts or septa, that are larger than normal hepatocytes and with large, often multiple, pleomorphic nuclei
- nuclear-cytoplasmic ratio is normal since both nuclei and the cell as a whole become larger
large cell change
hepatocytes have high nuclear-cytoplasmic ratio and mild nuclear hyperchromasia and/or pleomorphism
- these hepatocytes often form tiny expansive nodules within a single parenchymal lobule
small cell change
devoid of cytologic or architectural atypia, but have been shown to be clonal and are probably neoplastic, rather than simply large cirrhotic nodules
- portal tracts are still present within these nodules, often in near normal distribution
- blood supply remains a mix of portal venous and hepatic arterial blood
low-grade dysplastic nodules
cytologic (small cell change)or architectural features (occasional pseudoglands, trabecular thickening) suggestive of overt HCC
- such atypia often presents as a subnodule within the larger nodule
- portal tracts are fewer in these higher grade nodules and arteries feeding the growing lesion gradually come to predominate with portal venous flow
- overt HCC may then arise within the dysplastic nodules, eventually overgrowing it
high grade dysplastic nodules
may appear grossly as:
- unifocal (usually large) mass
- multifocal, widely distributed nodules of variable size
- diffusely infiltrative cancer
HCC
liver enlargement, the diffusely infiltrative tumor may blend so imperceptibly into a background of cirrhosis that it might not be apparent by imagine
- may be pale compared to surrounding liver or they may have a variegated appearance reflecting different differentiation states (white=abundant stroma, yellow=fatty change, green=when well-differentiated malignant hepatocytes make bile)
HCC
when do intrahepatic masses, be either vascular invasion or direct extension, become more likely?
once tumors reach 3cm
usually small, satellite tumor nodules around the larger, primary mass
- vascular route is the most likely route for extrahepatic metastasis, especially by the hepatic venous system
intrahepatic masses
when is tumor recurrence likely to occur in a transplanted liver?
when venous invasion is identified in HCC-bearing explanted livers, due to the seeding of circulating tumor cells in the transplant recipient
range from well-differentiated to highly anaplastic lesions
- the better differentiated are comprised of cells that look much like normal hepatocytes and grow in structures that are distortions of normal
HCC
a distinctive variant of HCC, constituting less than 5%
- most occur under the age of 35, without gender predilection or identifiable predisposing conditions
- presents as single, large hard “scirrhous” tumor with fibrous bands coursing through it
- microscopically, comprised of well-differentiated cells rich in mitochondria (oncocytes) growing in nests or cords separated by parallel lamellae of dense colagen bundles
fibrolamellar carcinoma
small lesions at the time of dx, as they rapidly cause obstructive features
- most tumors appear as fir, gray nodules within the bile duct wall
- some may be diffusely infiltrative lesions, others are papillary, polypoid lesions
extrahepatic cholangiocarcinomas
these lesions occur in the noncirrhotic liver and may track along the intrahepatic portal tract system creating a branching tumor within a portion of the liver
- alternatively, a massive tumor nodule may develop
intrahepatic cholangiocarcinoma
typical adenocarcinomas
- produce mucin
- most are well-moderately differentiated with clearly defined glandular/tubular structures lined by malignant epithelial cells
- typically incite marked desmoplasia
- lymphovascular and perineural invasion are both common
cholangiocarcinoma
