netpath notes Flashcards
what does hematoxylin do?
basic dye that stains acids blue = basophilic
nucleic acids of nuclei will therefore be blue
rER can aso stain blue because of the high RNA content
what does eosin do?
acid dye that stains basic structures red to pink = acidophilic/eosinophilic
most cytoplasmic elements are pink
what does it mean for a substance to be amphophilic?
stains with both H and E dyes => blue-pink color
what is the trichrome stain for?
used to identify connective tissue
collagen = blue to green
nuclei = black
cytoplasm = brick-red
what is the reticulin stain for?
for reticulin (type of fiber in connective tissue - made of type III collagen - secreted by reticular cells) stains black
what is the PAS stain for?
for structures with a high proportion of carbohydrate macromolecules (such as glycogen, glycoprotein, proteoglycans)
such as connective tissues, mucus, and basal laminae
will not stain for collagen
will stain for fungi
stains basal membrane dark
what does mucicarmine stain for? what is mucin?
colors epithelial mucins rose to red
mucins = chemically heterogeneous group of glycoprotein substances secreted by a variety of cells, including many glandular epithelial cells (aka mucus)
mucicarmine therefore stains for secretory epithelial cells
what is prussian blue used to stain for?
for iron - makes iron a dark blue
how would you detect iron in tissue?
in H&E, it’ll look rusty colored
prussian blue will stain it blue
what is the grocott methenamine silver (GMS) stain for?
stains cell walls of fungi black
blue counterstain used to visualize underlying tissue
used to visualize organisms in tissue
what is the acid fast stain used for?
to visualize organisms in the tissue
magenta-color stain is held in organisms after treatment with alcohol - used for mycobacteria such as tubercle bacilli
how are brown stains made (procedure)?
type of immunostaining
first antibody is to whatever’s being stained for (eg rabbit anti-IgG) and second is for the first antibody (eg mouse anti-rabbit) and has peroxidase, which will turn the regions where the antibody attached brown
what will a liver stained with reticulin look like?
liver cords are bordered by reticulin
portal triad area is rich in reticulin
which stains can be used to stain for microorganisms?
AFB - can see mycobacteria
GMS - for fungi
PAS - most fungi
what causes caseous necrosis?
certain types of infections, specifically those caused by mycobacteria and fungi
how will caseous necrosis appear different from liquefacative or coagulative necrosis?
won’t be complete cell dissolution as in liquefactive
but also won’t have crisp preservation of cell outlines as in coagulative necrosis
where would you expect to see fat necrosis?
areas that have experienced trauma
but most often result of action of lipases (then it’s enzymatic fat necrosis)
most commonly seen in acute pancreatitis because acinar cells get injured and activate and release pancreatic enzymes that destroy the pancreatic tissue and fat cells around the gland
breat, pancreas, subcutaneous tissue
how would fat necrosis appear histologically?
white in gross sections
amorphous in microscopic
can still see outlines of the dead adipocytes
what makes up the amorphous material seen in fat necrosis?
the cells die and release TG
the TG is converted to free FA
FA complex with Ca => soaps
how would fatty liver appear histologically?
in gross images, yellow-grey color (should be brown-red)
would feel slimy or greasy
fat would be in hepatocytes
what is stromal fatty infiltration?
when fat cells grow between parenchymal cells
occurs in obese individuals particularly and also in the elderly if their organs undergo atrophy - normal cells replaced by fat
what types of changes in hyalin might you see histologically? when would you see these changes?
homogenous glass pink arterial wall in patients with diabetes mellitus
using trichrone stain, can detect that this wall has more collagen than would be normal
in amyloidosis (deposition of amyloid in cells) - in glomerulus
mallory bodies (see other card)
what are mallory bodies? what do they look like histologically? what patients would you expect to see them in?
aggregates of intermediate filaments
in hepatocytes of patients with alcoholic hepatitis mostly
glassy, eosinophilic appearance
what does hyaline mean?
refers to a homogenous, glassy pink appearance in routine H&E sections
what is hemosiderin? what does it mark for?
form in which iron is stored in cells
marker of previous hemorrhage
what are anthracotic particles? where would they be found?
carbon dust in inspired air that is phagocytosed by pulmonary macrophages
appear in cytoplasms of macrophages as fine black particles
in lung - smear of sputum
what is hemosiderin? where would you expect to see it? what would it look like histologically?
golden brown pigment - breakdown product of hemoglobin
gets phagocytized by macrophages
found in areas where there was a hemorrhage
will stain blue with prussian blue stain
will be brown/rust-colored in H&E
what is lipofuscin (aka lipochrome)? what would it look like histologically? what cells would you expect to see it in?
wear-and-tear pigment - waste/indigestible residues of autophagic vacuoes formed during aging and atrophy
finely granular yellow-brown pigment in cytoplasms
see in cells that have really long life spans such as myocardial fibers and neurons
what is brown atrophy?
when lipofuscin gives an organ a brownish hue
this isn’t dangerous to the organ
how would Ca salts appear histologically?
usually basophilic and so are blue in H&E
what is the usual consequence of ischemia?
coagulative necrosis
what is the usual consequence of infection?
liquefactive necrosis if inflammatory response involves may neutrophils
if inflammatory response is granulomatous, may be caseous necrosis
what is hypertrophy? is it reversible?
enlargement of cells without an increase in cell number (so organ gets bigger because cells get bigger, rather than there being more cells)
very often reversible
how would hypertrophy appear histologically?
cells are larger
nuceli become square
what is hyperplasia? is it reversible?
increase in the number of cells of an organ but cells are normal size (so organ gets bigger but cells don’t)
may be reversible depending on what’s driving it - if hormonal stimulus and hormone is removed many of the new cells will become apoptotic and die
what cells can cause hyperplasia?
two cell types can be stimulated to divide by trophic factors:
1: labile cells - constantly dividing (eg bone marrow stem cells, intestinal crypt epithelial cells)
2: stable - enter cycle only if there’s a need (eg liver cells, renal tubular cells)
what would hyperplasic tissue look like?
in breast, lobules hypertrophy, so much more cellular - acini become bigger, more complex, and there’s more of them
in prostate - lots of infoldings in glands
what is metaplasia? what are some examples?
reversible phenomenon when one adult cell type is replaced by another - phenotype changes
replacement tissue can survive under circumstances when normal, more fragile tissue couldn’t
usually under pathological stimulus
can develop to dysplasia
eg - normally have pseudostratified columnar epi in airways - cigarette smoking will cause them to become nonkeratinized squamous epithelium
or if acid indigestion - get change to mucous secreting epithelium in esophagus to protect it - replaces squamous epithelium = Barrett’s esophagus
what is dysplasia?
deranged development
lack of appropriate maturation
but not neoplastic yet
at gross level = abnormal development - overall disorganization of cells of various types and not failure of normal differentiation of a single cell type
but more common at the histologic level - at cellular level implies alteration of size, shape and organization of cells
often failure of normal diff of one type of cell
what would dysplasia look like histologically?
severe will have atypical cellular changes eg nuclear enlargement and inappropriate increase in number or location of mitotic cells
disordered maturation, enlarged nuclei, failure of a normal degree of progressive differentiation (ie from more internal to external layers)
what is hypoplasia?
failure to grow to normal size (as opposed to atrophy, which is shrinking to a smaller than normal size)
what happens if growth stimulant is applied to “permanent” cells?
nuclei may enlarge
what is atrophy? what would it look like histologically?
cells shrink, but there’s no decrease in the number of cells
organ therefore decreases in size
often see just nuclei (no cytoplasm)
