Histopathology ✔ Flashcards
what is the blood supply of the liver?
portal vein & hepatic artery (dual)
what are the 6 types of cells in the liver?
hepatocytes bile ducts Kupffer cells (immune) stellate cells blood vessels/cells endothelial cells
what is the maturity process of liver cells?
born in ‘zone 1’ and die in ‘zone 3’ so most metabolic enzymes near zone 3. Most active metabolites in zone 3 (think acetaldehyde from alcohol, paracetamol-induced disease). Zone 3 is nearest to vein. Zone 1 - arteries.
what is the ‘limiting plate’ in the liver?
site of much pathology, a line on the slides between the portal triad & the hepatocytes outside it
what is unique about the endothelial cells on the hepatic sinusoid?
not attached to any BM, not attached to each other meaning that blood can easily pass between endothelial cells and the hepatocytes
what is the space of Disse in the liver?
the site of the stellate cells in the liver. lie between the hepatic sinusoid endothelial cells and the hepatocytes
what is the cellular difference between normal and diseased liver with regards to Stellate cells?
stellate cells in Space of Disse activate - flatten out. the endothelial cells join up - losing the gaps that allow blood to travel between. the stellate cells also begin to deposit collagen which leads to formation of a scar matrix. the fenestrae are lost and the microvilli of hepatocytes are lost so diffusion cannot occur as normally.
what is the cellular definition of liver cirrhosis ? (4 parts)
1) whole liver involved
2) fibrosis
3) nodules of regenerating hepatocytes
4) distortion of liver vascular architecture (intra/extra hepatic shunting of blood)
what are 2 main causes of fatty liver disease?
alcohol, insulin resistance
what type of cirrhosis does alcohol cause?
fatty liver disease, micronodular
what are the 3 main complications of cirrhosis?
1) portal hypertension (loss of blood flow shunts)
2) hepatic encephalopathy (blood not cleared)
3) HCC
T or F: cirrhosis is reversible
T. It may be reversible (as of a decade ago) with aggressive treatment of the underlying cause
What are the two main causes of acute hepatitis?
1) viruses (Hep A-E)
2) drugs (antibotics esp)
what is the presence of acute hepatitis on histopathology?
spotty necrosis
what are 3 main causes of chronic hepatitis?
1) viruses (Hep B,C,D)
2) drugs (eg isoniazide)
3) autoimmune
how do we classify chronic liver disease?
severity of inflammation - grade
severity of fibrosis - stage
describe histopath of portal inflammation:
no inflammation crosses the limiting plate
describe histopath of interface hepatitis: (inflammation induced apoptosis)
‘piecemeal necrosis’
inflammation across the interface (portal triad and hepatocytes)
how does intrahepatic shunting look on a cirrhotic liver?
‘bridging fibrosis’
what are the 3 types of alcoholic liver disease?
1) fatty liver
2) alcoholic hepatitis
3) cirrhosis
what does fatty liver look like re: histopath?
1) pale, enlarged
2) microscopically - each cell is full of fatty changes (large droplet fatty change)
in viral hepatitis what is the key inflamed cell?
the lymphocytes
in fatty liver, what is the key inflamed cell?
neutrophil polymorph
what is seen in alcoholic hepatitis histologically?
Mallory Denk bodies/Mallory hyaline (pink colored)
inflammation
fibrosis around individual hepatocytes (esp in zone 3)
what is the histological view of alcoholic cirrhosis?
fatty, pale, nodules small (micronodular)
microscopically - nodular hepatocytes, fibrosis, some fat
what is the cause of NAFLD (non-alcoholic fatty liver) including NASH?
histologically - alcoholic liver disease
cause - raised BMI, insulin resistance, diabetes
what is histologically PBC (primary biliary cirrhosis)?
bile duct loss associated with chonic inflammation (with granulomas) due to anti-mitochondrial antibodies
what is the cellular cause of PSC (primary sclerosing cholangitis)?
periductal bile duct fibrosis leading to loss. Strongly associated with ulcerative colitis, increased risk of cholangiocarcinoma. Diagnosis via ERCP
what is the cellular cause of hemochromatosis:
gene on chromosome 6 (HFE gene) leading to increased gut iron absorption leading to secondary iron deposition parenchymal damage to organs.
(‘bronzed diabetes’)
histo - parenchymal iron; ‘full of iron’
Prussian blue = iron stain
chocolate brown liver (macro)
cellular cause of hemosiderosis
iron deposition in macrophages - hemosiderosis from blood transfusions. Does not produce scarring or cirrhosis.
cellular cause of Wilson’s disease
genes on chromosome 13 leading to excess of copper in the body from failure of excretion by hepatocytes so it accumulates in the liver & CNS (hepato-lenticular degeneration)
cellular cause of autoimmune hepatitis:
interface hepatitis with plasma cells due to anti-smooth muscle actin antibodies. Responds to steroids.
cellular cause of alpha one antitrypsin deficiency:
blood deficiency, not liver. Liver has excess of alpha one antitrypsin - cannot be secreted from hepatocytes so it stays there and damages them in the RER of cells. Leads to intra-cytoplasmic inclusion bodies and then further to hepatitis/cirrhosis
paracetamol -liver damaged, histologically
it is the cells in zone 3 that are heavily damaged. those right by the arteries tend to survive well. Worse with alcohol because alcohol is liver enzyme-inducer
causes of liver granulomas: (4)
PBC, drugs, TB, sarcoidosis
3 types of liver tumors that are benign:
liver cell (hepatocytes) adenoma, bile duct (cholangi cells) adenoma, hemangioma (endothelial cells)
malignant liver tumors can be primary or secondary. what are the 4 types of malignant primary liver tumors?
hepatocellular carcinoma/HCC
hepatoblastoma
cholangiocarcinoma
hemangiosarcoma
which is the commonest carcinoma in the liver?
metastatic adenocarcinoma
which of these is not associated with fatty changes in the liver?
a) diabetes
b) hep B
c) hep C
d) alcohol
Hep B
which of these is not associated with genetic hemochromatosis?
a) cirrhosis
b) diabetes
c) Kaiser-Fleischer rings
d) myocardial damage
c) Kaiser-Fleischer rings
what are the 6 skin reaction patterns?
vesiculobullous spongiotic psoriasiform lichenoid vasculitic granulomatous
histological view of pemphogoid bullae reaction skin
IgG and C3 are destroying the ‘bottom layer of foundation of the house’ so basement membrane destroyed, elastase produced, epidermis is raised. This present as sub-epidermal bullae. Agitation of IgG and C3 along basement membrane in a linear fashion of band on immunofluorescence
sub-epidermal split
histological view of pemphigus vulgaris
IgG reacting against the keratinocytes so that the split occurs mid-epidermal
‘cement has been destroyed, foundation is secure, but the bricks of the house are free-floating’
histological view of pemphigus folicaeous
the ‘roof’ has fallen off so that the keratinocytes are intact but the rest have fallen off
–> epidermis split
Discoid eczema or contact dermatitis are examples of spongiotic skin reaction. What is the histological facts of it?
-atopy
- epidermis falling apart
(‘cement of house is soggy)
-whiteness around keratinocytes because fluid has stretched them apart but not pulled them apart
-eosinophils within infiltrate in underlying dermis
Psoriasis on the extensor surfaces, is an example of a t-cell mediated reaction process, a psoriasiform
- perikeratosis on the top layer of the dermis
- very rapid turnover leading to loss of granular cell layer at the top
- epidermis looks thicker
- neutrophils in the super-epidermal layer instead of eiosinphils
histological parts of a lichenoid reaction pattern (think of lichen planus)
- white striae within buccal areas (wickham’s striae)
- destroying bottom layer/basement membrane
- can’t see the difference between dermis and epidermis
- lymphocytes spread throughout because attacking the skin
licen planus is an example of which type of inflammatory reaction pattern?
lichenoid
where in the epidermis does the bullae in pemphigus vulgaris occur?
mid-epidermal
histological view of seborrheic keratosis
proliferation of basal keratinocytes
histological view of sebaceous cyst
occlusion cyst
cyst lined with epithelium same as epidermis
hair or sebaceous material going through cyst
histological view of BCC
Histologically, BCC is characterized by clusters of darkly staining basaloid cells with a palisade arrangement of nuclei at the periphery of the clusters. The stroma adjacent to the tumor epithelium has a characteristic blue “myxoid” appearance, and clefts often separate the nests of basaloid cells from the surrounding dermal stroma. Don’t kill people because they don’t metastasize.
histological view of Bowen’s disease
atypical mitotic figures, atypical keratinocytes
dysplasia
histological view of SCC
will progress to LNs and metastasize.
islands invaded into the dermis from the squamous epithelium
histological view of naevus (moles)
classified based on where the melanocytes nests in the dermis -
junctional naevus: within epidermis
compound naevus: within epidermis & dermis
intradermal naevus: within dermis
histological view of malignant melanoma:
Histologically, melanomas are asymmetrical and poorly circumscribed lesions with architectural disturbance and usually marked cytological atypia. Specific features include consumption of the epidermis, pagetoid spread of melanocytes, nests of melanocytes with variable size and shape (which may be confluent and lack maturation), melanocytes within lymphovascular spaces, deep and atypical mitoses and increased apoptosis. Mitotic figures are common.
which common skin cancer does not metastasize?
BCC
how do mesangial cells work in the kidneys?
stop bits of capillary wall to stop any leakage - connects the cells to the meansgium (like mesentery of the kidney)
Cywhat are the components of the kidney filtration barrier?
1) endothelial cells - fenestrated
2) BM - primarily type 4 collagen
3) podocyte - with foot processes on the outside of BM
what is the podocyte responsible for in the kidney?
selective filtration at the kidney filtration barrier
which 2 cellular processes can cause glomerular disease?
failure to filter an adequate amount of blood or leaky barriers that fail to maintain adequate barrier function
what cellular process causes immune-mediated glomerulonephritis?
immune complexes forming and causing damage to the glomeruli, or even cause leakages in the glomerular barriers. May be auto-antigens (eg SLE) or derived from infectious organisms. They may also be slow or quick onset.
what is the cellular process of PCKD?
AD inheritance of PKD1 or PKD2 genes. CKD usually onsets by 40 -50 years. Cysts arise from all portions of the kidneys & can also be seen in liver and cause aneurysms
what is the cellular process leading to AKI?
a rapid loss of glomerular filtration and tubular function leading to rapid imbalance of electrolytes and reduced GFR. acidosis, hyperkalemia, fluid overload w/hypertension, increased creatinine & urea
how do we classify renal failure?
pre-renal, renal, post-renal
what is the cellular process of ATN (acute tubular necrosis)?
commonest cause of acute renal failure from damage to tubular epithelial cells by toxins or ischemia.
histologically what is seen in acute tubular injury?
- flattened epithelium
- granular casts throughout
why does acute tubular injury cause failure of glomerular filtration?
blockage of tubules by cast
leakage of fluid from tubules to interstitium (reduced flow)
secondary hemodynamic changes
what is the cellular process of acute glomerulonephritis?
acute inflammation of glomeruli leading to reduction in GFR; see red/white blood cell casts in the urine with oliguria. Almost always associated with glomerular crescent - accumulation of inflammatory cells within Bowman’s space from breaks in the glomerular BM. Silver stain will stain BM
what are 3 causes of crescentic glomerulonephritis?
1) pauci -immune (ANCA antibodies)
2) anti-GBM disease
3) immune complex (SLE, IgA nephropathy)
what is the cellular process of anti-GBM disease?
antibodies against glomerular BM, esp the type 4 collagen. Characterized by IHC showing linear deposition of IgG on GBM. Antibodies may also bind to alveolar basement membrane and may cause a lung hemorrhage.
what is Goodpasture’s syndrome?
lung hemorrhage & crescentic glomerulonephritis
histopath of anti-GBM disease?
Characterized by IHC showing linear deposition of IgG on GBM
cellular process of pauci immune glomerulonephritis?
inflammation of blood vessels elsewhere often too - vasculitic rash or lung hemorrhages
ANCA antibodies. most common crescentic glomerulonephritis.
histopath of pauci immune?
large destructive crescentic damage that spreads beyond Bowman’s capsule into the interstitium
what is thrombotic microangiopathy?
platelet thrombi within glomeruli, arterioles, or arteries leading to thrombi. Usually develop MAHA/HUS. RBC have been damaged by fibrin.
blood film in thrombotic microangiopathy?
RBC shows shistocytes (those damaged by the fibrin) , anemia
histopath of amyloidosis?
pink in an H&E stain; depositions of extracellular proteinaceous material. Stains Congo-Red, looks green under polarized light.
Stains Congo-Red, looks green under polarized light. What’s the diagnosis?
amyloidosis
two main proteins in amyloidosis in the kidney?
SAA (serum amyloid associated protein) and AL (amyloid light chain protein)
what is the main cell involved in primary kidney glomerular disease?
podocytes -
in what kidney disease do glomeruli look normal other than effacement of the foot processes in the podocytes?
minimal change kidney disease; most common children’s nephrotic syndrome
what is the cellular change in minimal change kidney disease?
glomeruli look normal other than effacement of the foot processes in the podocytes
what is the cellular change in focal/segemental glomerulosclerosis?
similar to minimal change kidney disease BUT glomeruli develop segmental scars
cellular changes of membranous glomerulonephritis?
immune deposits on outside of BM; no inflammatory changes. many associated with phospholipid A2 receptor antibodies if primary.
what are the causes of membranous glomerulonephritis?
autoantibody to phospholipid A2 receptor (primary)
SLE, infection, drugs, malignancy (secondary)
what is the cause of isolated microscopic hematuria?
thin basement membranes hereditary defect in type 4 collagen, IgA nephropathy.
histopath difference in microscopic hematuria:
IgA nephropathy or hereditary defect in type 4 collagen leading to thin basement membranes
commonest cause of glomerular nephritis worldwide?
igA nephropathy
what is the cellular difference in igA nephropathy?
igA deposits in glomeruli
what cell forms the outer layer of the glomerular filtration barrier?
podocytes
what percentage of end stage renal disease is due to autosomal dominant PCKD?
10%
what type of amyloid is formed in patients with multiple myeloma?
AL
what’s the commonest cause of nephrotic syndrome in children?
minimal change disease
antibodies to phospholipid A2 receptor are associated with what form of glomerulonephritis?
primary membranous
what are the 3 layers of the gut?
muscularis propria, submucosa, epithelium (squamous in esophagus, columnar elsewhere)
what is the main inflammatory cell involved in acute oesophagitis?
the neutrophil polymorph
what histopath changes are seen in GORD/GERD?
commonest cause of acute oesophagitis.
see necrotic slough, inflammatory exudate, granulation tissue and later on, fibrosis. This is the commonest cause of oesophagitis.
the difference between an acute & chronic ulcer?
the presence of fibrosis & scarring at the base of the chronic ulcer
what are the cellular changes in Barett’s esophagus?
re-epithelization by metaplastic columnar epithelium usually with goblet cells (intestinal type epithelium)
what are the histological changes in esophageal cancer?
squamous epithelium, underneath is glandular neoplasm. Glands full of mucus. Adenocarcinoma is the commonest cause of esophageal cancer in england
where do adeno & SCC of the esophagus tend to be?
SCC- tends to be higher up in esophagus; assoc with alcohol and smoking
adenocarcinoma - tends to be lower down in the esophagus. related to GERD.
histopath differences in SCC esophageal cancer?
have fibrin bridges & make keratin
cellular insult causes of chronic gastritis:
A - autoimmune (MALT)
B - bacteria (H Pylori)
C - chemicals (NSAIDs, bile)
when do you find lymphoid follicles in the stomach?
only if patient has had H Pylori infection
what does H Pylori infection cause?
chronic gastritis/ulcer
CLO - intestinal dysplasia
adenocarcinoma
lymphoma in stomach (MALT tissues)
how does one get H Pylori infection and what is the process in the body?
8x increased risk of gastric cancers once infected. Infection is via cag-A + H Pylori to inject toxins into intercellular junctions for bacteria to attach more easily. This leads to chronic inflammation. Treat with antibiotics and get rid of increased cancer risk
when do you see goblet cells in the stomach?
only with chronic inflammation or dysplasia.
what is the most common type of malignant tumor in stomach?
> 95% are adenocarcinomas
what are the two types of stomach adenocarcinomas and describe them:
intestinal adenocarcinoma - well differentiated glands; better prognosis
diffuse adenocarcinoma - poorly differentiated (Linitis plastica), includes signet ring cell carcinoma
what are the 5 types of potential stomach carcinomas
lymphoma (MALToma) squamous cell GIST (gastrointestinal stromal tumors- soft tissue; Cahal cells) neuroendocrine tumors adenocarcinoma (95%)
what types of cancer are MALTomas?
lymphomas; marginal zone
what are the 2 most important intestinal infections related to gastritis or duodenitis?
giardia, CMV
MALToma in the duodenum is associated with…
celiac’s disease (enteropathy associated T-cell lymphoma)
MALToma in the stomach is associated with…
H Pylori infections (MALT activation)
T or F: most esophageal and gastric cancer arise from pre-existing adenomas
false
in a patient with celiac’s disease who is currently on a gluten diet, what is the histopath most likely to show?
atrophy & intra-epihtelial lymphocytes
which of the following is not a cause of chronic gastritis?
a) autoimmune
b) infection
c) drugs
d) metabolic disease
metabolic disease
what are the diaphysis, epiphysis, metaphysis in bone?
diaphysis - long part of bone
metaphysis - connecting plate between dia & epi
epiphysis- knuckle shaped end (think, epithelium)
what are the two types of bone?
cortical & cancellous
describe cortical bone:
long bones that make up 80% of the skeleton; they are appendicular and 80-90% calcified. They are mainly mechanical and protective.
describe cancellous bone:
the vertebrae & pelvis. They make up 20% of the skeleton in an axial fashion. They are only 15-25% calcified and serve mainly a metabolic purpose.
describe cortical bone microanatomy:
from inside –> out
trabecular lamellae –> interstitial and concentric lamellae layered –> circumferential lamellae
T or F: calcified cortical or cancellous bone stains pink on H&E
True
what are the 3 types of bone cells and what do they do?
osteoblasts - build bone by laying down osteoid
osteoclasts- multinucleate cells of macrophage family that absorb/chew up bones
osteocytes - osteoblast-like cells which sit in bony lacunae
what cells show up on silver staining of cancellous bones?
osteocytes
canaliculae
what is the etiology of primary & secondary osteoporosis?1
primary - age, post menopausal
secondary - drugs, systemic disease
what are risk factors for osteoporosis?
low BMI, poor diet/dec. vit D intake, female, older age, smoking/etoh, early menopause, low testosterone, CKD, steroids
there is ‘high turnover’ osteoporosis and ‘low turnover’ osteoporosis. what is the difference?
high turnover - increased osteoclast (resorption)
low turnover - decreased osteoblast (making less)
what are the two types of osteomalacia?
lack of vitamin D or lack of PO4
when do we see issues with ‘Looser’s zone’?
win osteomalacia - horizontal fractures in looser’s zones
what are the two causes of primary hyperparathyroidism?
parathyroid adenoma (85-90% of the time) or chief cell hyperplasia
what are the two causes of secondary hyperparathyroidism?
malabsorption/vit D deficiency
renal deficiency
Renal osteodystrophy describes all of the skeletal changes in CKD, what are they?
- osteitis fibrosa cystica (increased bone resorption)
- osteomalacia
- osteosclerosis
- growth retardation
- osteoporosis
what are the biochemical changes in renal osteodystrophy?
hyperphosphatemia - PO4 retention hypocalcemia - decreased Vit D secondary hyperparathyroidism metabolic acidosis aluminum deposition
what would be some clinical indications for a bone biopsy?
suspected osteomalacia
dx classification of renal osteodystophy
osteopenia in patients < 50 years
osteopenia assoc. with abnormal Ca metabolism
what is the cellular process behind Hirschsprung’s disease?
absence of ganglion cells in gut myenteric plexus so that distal colon fails to dilate. Presents with constipation, abdo distension, ‘overflow’ diarrhea
what chromosomal abnormality is Hischsprung’s disease associated with?
Down’s syndrome
what age group is most associated with small bowel volvulus?
infants
what age group is most associated with large bowel volvulus? (sigmoid colon/caecal)
elderly