Liver Flashcards
A cystic structure was removed from the liver of a man with HBV. A section is shown in this image. What is the histological feature and what is the diagnosis?
Dx: Hydatid cyst/echinococcal cyst wall.
Histo features: Classic features of echinococcal cysts include a laminated wall and a thin germinal layer . Note the absence of any inflammatory changes within the laminated wall.
What is the functional unit of the liver (histologically) and what is it made up of?
Hepatic lobule
Composed of hepatocyte plates surrounding a central vein with portal tracts at the periphery
What is demonstrated in this image? Describe the components
Portal triad.
Hepatic artery: lined by endothelium and a thin muscular layer, approximately the same diameter as a bile duct
Portal vein: lined by endothelium
Bile duct: lined by cuboidal epithelium, approximately the same diameter as a hepatic artery.
What is demonstrated in this image? What are the key features?
Lobule: functional unit centered around central vein to include surrounding portal triads
Periportal zone / zone 1
Higher content of oxygen and nutrients
Highest metabolic activity
Least susceptible to ischemia and toxic injury
Midlobular zone / zone 2
Centrilobular zone / zone 3
Most susceptible to ischemia and
toxic injury
Liver biopsies
Routine stains used?
Routine stains:
Trichrome: highlights collagen fibers to
assess and stage fibrosis
Reticulin: highlights reticulin fibers to
assess hepatic plates for expansion or
collapse
Periodic acid-Schiff (PAS): highlights
glycogen
Periodic acid-Schiff with diastase (PASD):
Highlights the basement membrane of
bile ducts and ductules
Stains abnormal alpha-1 antitrypsin
globules in hepatocytes in the setting
of alpha-1 antitrypsin deficiency
Iron: aids in evaluating iron deposits in
hepatocytes and Kupffer cells
Dx liver lesion.
Key features?
Hydatid (echinococcus) cyst showing accelular lamellate with protoscolices.
Cyst wall has 3 structural components:
Outer acellular laminated membrane (1 mm thick)
Germinal membrane (a transparent nucleated lining)
Protoscolices, attached to the membrane and budding from it
Outer fibrotic layer with granulation tissue with increased eosinophils also exists
HCC
Architectural patterns and which is a/w a worse px?
4 principal growth patterns, including trabecular, pseudoglandular, solid and macrotrabecular (in decreasing order of frequency)
50% of cases have mixed patterns; macrotrabecular pattern is associated with worse prognosis
liver bx
dx and key feature demonstrated
HCC trabecular pattern
Liver excision, dx and key features demonstrated
HCC with pseudoacinar pattern
HCC
IHC
Arginase1: cytoplasmic or nuclear; useful in confirming hepatocellular differentiation; highly sensitive and specific, thus more useful than HepPar1 for poorly differentiated hepatocellular ca
HepPar1: cytoplasmic and granular; overall highly sensitive but 50% of poorly differentiated hepatocellular carcinoma lose expression
Glypican 3: cytoplasmic; high sensitivity in poorly differentiated and scirrhous hepatocellular carcinoma but low sensitivity in well differentiated hepatocellular carcinoma (nonneoplastic liver is negative)
AFP: cytoplasmic; highly specific but low sensitivity; frequently negative in well differentiated hepatocellular carcinoma
Polyclonal CEA, villin and CD10 reveal canalicular pattern; limited sensitivity in poorly differentiated hepatocellular carcinoma
Albumin ISH: high sensitivity for primary liver carcinoma, although this can also be positive in other adenocarcinomas not of biliary origin
Pancytokeratins (MNF116 or OSCAR) and CAM5.2 (CK8 / CK18) are positive
Reticulin: highlights the thickened hepatocyte plates (> 3 cell thick); see also negative stains below
liver cystic lesion
dx
Key features
IHC
DX: mucinous cystic neoplasm (low/intermediate-grade dysplasia)
Essential: grossly visible multilocular cystic lesion, exclusively in female patients, with no communication to the bile duct system; cystic lesion with cuboidal and columnar neoplastic epithelia, at least partly positive for mucin staining and with variable atypia; ovarian-like, mesenchymal stroma, at least focally positive for ER and/or PR.
IHC: The stromal cells are immunoreactive for ER, PR, and α-inhibin.
hepatocellular adenoma
subtypes (4), key histo features and IHC
- HNF1A-inactivated HCA
- Inflammatory HCA
- Beta catenin activated HCA (b-HCA)
- Beta-catenin activated inflammatory HCA
H-HCA: lobulated contours and exhibit diffuse macrosteatosis/microsteatosis, ballooned and clear cells and occasional pseudoglands. Microadenomas present in the b/g.
IHC: Liver fatty-acid binding protein (LFABP) absent in tumour and cytoplasmic staining in normal liver). GS absent or positive around veins, or scattered patchy staining.
IHCA: characterised by sinusoidal dilatation, congestion, foci of inflammation, thick arteries and more or less obvious ductular reaction leading to an aspect of pseudoportal tracts. Fibrotic bands and ndoular organization due to remodelling can be misleading.
IHC: CRP/serum amyloid A positivity (usu diffuse) w/ sharp demarcation from surrounding liver. GS absent or (+) around veins, mainly atthe peirphy of ndoule.
B-HCA - can sometimes present some cytoarchitetural atyipa, pseudoglands, and pigments (lipofuscins, bile).
B-IHCA: features of both IHCA and b-HCA.
Both b-HCA and b-IHCA can show focally decreased reticulin. Both b-HCA and b-IHCA can show GS overexpression depending on the mutation types (if exon 3 -> typically diffuse homogenous staining often nuclear b-catenin). NB: exon 3 mutation = high risk of HCC. Exon 7/8 mutation: no/low risk of HCC>
HCC, subtypes? (8)
Fibrolamellar, scirrhous, clear cell type, steatohepatitic, chromophobe, macrotrabecular massive, neutrophil-rich, lymphocyte-rich.
Which HCC subtype occurs only in non-cirrhotic livers?
fibrolamellar
difference between early HCC and small progressed HCC? (compare and contrast)
grading of HCC
