Pre-Analytical Stage (Part 1 | F) Flashcards
True or False
There are already anatomists as early as 17th century
True
What are the 2 concepts / fields under anatomic path?
1) Autopsy
2) Surgical Path
3) Cytopath
True or False
Modern day pathos now can bridge the gap between the beginning of disease and its end stage
True
True or False
The nature of work and type of sxs in anatomic path are not highly complex
False, because the nature of work and type of sxs in anatomic path are highly complex
What are the 3 stages present in anatomic path?
1) Pre-analytical
2) Analytical
3) Post-analytical
What are the 2 principles (that are derived / adapted from clinical path) employed in anatomic path?
1) Quality assurance
2) Quality management
What is the process involved in surgical path? Explain it and its principle
1) Pt (who is the source of all sxs) has a complain
2) Hence, pt went to the surgeon (who extracts relevant clinical info and manages the lesion [either via biopsy / excision for dx])
3) The sx (diseased organ / tissue) removed by the surgeon from the pt will be submitted in the histopath lab (where sx is received and where sx accessioning occurs)
4) Then grossing of sx is also done in the histopath lab
5) Then sx will be stored (duration is dependent)
6) Then the grossed tissue will be processed by histotech / medtech
7) Then histotech / medtech will produce a slide
8) The slide produced is the interpreted by the patho and is translated into a std report (report generation)
9) The report generated will be relayed back to the surgeon / clinician (in a timely manner)
10) Then pt will start treatment (/ if additional treatment is present) subsequently
11) Then once dx is present, it’s the time for report generation (whereas this report is the result)
What are the steps involved in sx processing?
1) Embedding
2) Cutting
3) Deparaffinization
4) Staining
5) Clearing
6) Mounting
7) Labeling
Who are the diff staffs composing the surgical lab?
1) Dependent managers
2) Medtechs / histotechs
3) Clerical support
4) Pathos (including residents)
5) Lab aids
What is the action / responsibility of department managers?
They are in-charge w/ the overall management of the section
What is the action / responsibility of the medtechs / histotechs?
They are in-charge of processing
What is the action / responsibility of the clerical support?
They are mostly stationed in the receiving, accessioning, and report generation steps
What is the action / responsibility of the pathos?
They are the ones who does the analysis
What are the purpose of histopathologic / cytology studies?
1) To diagnose
2) To confirm dx
3) To treat
4) To assess px
5) To assess treatment
6) To screen for disease
When / in terms of receiving histopathologic sxs, what should be noted?
1) Request forms
2) Sx containers
3) Fixative used
4) Logbooks / Sx accessioning
5) Charging
What is the purpose of fixation?
To preserve tissues permanently in as life-like state as possible
When should fixation be done (in the case of surgical path)?
As soon as possible after removal of the tissues
When should fixation be done (in / w/ autopsy)?
Soon after death
Why should fixation be done as soon as possible after the removal of the tissues (for surgical path) or soon after death (w/ autopsy)?
To prevent autolysis
True or False
There is a perfect fixative
False, because there is no perfect fixative
What is the fixative that comes the closest when it comes of it being a perfect fixative?
Formaldehyde
The type of fixative to be used is dependent on what?
1) Type of tissue present
2) Features to be demonstrated
What are the 5 major grps of fixatives (w/c are classified accdg to mechanism of action)?
1) Aldehydes
2) Mercurials
3) Alcohols
4) Oxidizing agents
5) Picrates
What are the fixatives under the grp of aldehydes?
1) Formaldehyde
2) Glutaraldehyde
What is the mechanism of action of formaldehyde?
The tissue is fixed by cross-linkages formed in the proteins, particularly between lysine residues
True or False
The cross-linkage formed in the proteins (via the use of formaldehyde) do harm the structure of proteins greatly, so that antigenicity is not lost
False, because the cross-linkage formed in the proteins (via the use of formaldehyde) does not harm the structure of proteins greatly, so that antigenicity is not lost
What is the fixative that is good for immunoperoxidase techniques?
Formaldehyde
What makes formaldehyde good for immunoperoxidase techniques?
The cross-linkages (formed in the proteins) does not harm the structure of proteins greatly, so that antigenicity is not lost
What is the other name for formaldehyde?
Formalin
What are the characteristics of formalin?
1) It penetrates the tissue well
2) But its penetration is relatively slow
3) It is the most forgiving of all fixatives when conditions are not ideal, and there is no tissue that it will harm significantly
What is the std solution of formaldehyde?
10% neutral buffered formalin (NBF)
What is the purpose of using a buffer?
It prevents acidity that would promote autolysis and cause precipitation of formol-heme pigment in the tissues
On what are formalin used?
For all routine surgical pathology and autopsy tissues when an H and E slide is to be produced
True or False
Due to the nature and characteristics of formalin (whereas it also smells bad), most clinicians and nurses should be careful in handling it
True
What is the mechanism of action of glutaraldehyde?
It causes deformation of alpha-helix structure in proteins
Is glutaraldehyde good to be used for immunoperoxidase staining? Why or why not?
No, because it causes the deformation of alpha-helix structure in proteins
What are the characteristics of glutaraldehyde?
1) It fixes very quickly
2) However, it penetrates very poorly
3) It gives the best overall cytoplasmic and nuclear detail
Since glutaraldehyde fixes very quickly, it is so good to be used for what?
Electron microscopy
What is the std solution of glutaraldehyde?
2% buffered glutaraldehyde
What is the mechanism of action of mercurials?
Its mechanism of in terms of fixing tissue is unknown
What is the component of mercurials?
Mercuric chloride
What are the fixatives under the grp of mercurials?
1) B-5
2) Zenker’s solution
What are the characteristics of mercurials?
1) These penetrate relatively poorly
2) These cause tissue hardness
3) These fixes fast
4) These gives excellent nuclear detail
Where can mercurials be best used / applied?
For fixation of hematopoietic and reticuloendothelial tissues
Since mercurials contain mercury, what must be done to these fixatives?
These must be disposed of carefully
What are the fixatives under the grp of alcohols?
1) Methyl alcohol (methanol)
2) Ethyl alcohol (ethanol)
What are the characteristics of alcohols?
1) These are protein denaturants
2) These are not used routinely for tissues because these cause too much brittleness and hardness
3) These are very good for cytologic smears
Why are alcohols very good for cytologic smears?
Because these act quickly and give good nuclear detail
Who are the professionals that are marketed w/ spray cans of alcohol fixatives?
Physicians (who does PAP smears)
As an alternative to spray cans of alcohol fixatives, can cheap hairsprays be used?
Yes, because these also do just as well compared to spray cans of alcohol fixatives
What are the fixatives under the grp of oxidizing agents?
1) Permanganate fixatives
a. Potassium permanganate
2) Dichromate fixatives
a. Potassium dichromate
3) Osmium tetroxide
What are the characteristics of oxidizing agents?
1) These cross-link proteins
2) But these cause extensive denaturation
3) Even if some of these have specialized applications, these are used very infrequently
What is the fixative under the grp of picrates?
Bouin’s solution
What is the component of picrates?
Picric acid
What is the mechanism of action of picrates?
It is unknown
What are the characteristics of picrates in comparison w/ mercurials?
1) These does almost as well as mercurials (in terms of nuclear detail)
2) But these does not cause as much hardness (like mercurials)
What is the characteristic of picric acid?
It is an explosion hazard (especially in dry form)
What is the characteristic of picric acid (as a solution)?
Everything it touches are stained yellow, including the skin
What are the factors affecting fixation?
1) Buffering
2) Penetration
3) Volume of fixative
4) Temperature
5) Concentration
6) Time interval
At what pH is fixation best carried out?
Close to neutral pH, in the range of 6 - 8
What is the fxn / purpose of buffering (/ buffer)?
Since hypoxia of tissues lowers the pH, a buffering capacity in the fixative is needed to prevent excessive acidity
Acidity favors the formation of what?
Formalin-heme pigment
What are the characteristics of the formalin-heme pigment present due to acidity?
These appears as black, polarizable deposits in tissue
What are the exs of common buffers?
1) Phosphate bicarbonate
2) Cacodylate
3) Veronal
Commercial formalin is buffered w/ what buffer and at what pH?
Phosphate; at a pH of 7
Penetration of tissues depends on what?
It depends upon the diffusability of each individual fixative (w/c is a constant)
What are the fixatives that penetrate the best?
1) Formalin
2) Alcohol
What is the fixative that penetrates the worst?
Glutaraldehyde
What is the capacity of penetration of mercurials and other fixatives?
Somewhere in between best and worst
What should be done to the tissue prior to fixation to prevent the interferences that may occur due to improper penetration of the fixative?
Section the tissues thinly (2 - 3 mm)
True or False
Penetration into a thick section will occur more rapidly than for a thin section
False, because penetration into a thin section will occur more rapidly than for a thick section
True or False
The volume of fixative is not impt, hence, it should not be considered / observed
False, because the volume of fixative is impt
What is the fixative to tissue ratio?
10:1
What happens if not enough / improper volume of fixative is used?
Ideal fixation is not achieved
What should be done to partially put a resolution when improper volume of fixative is used?
Change the fixative at intervals to avoid exhaustion of the fixative
What is the external action that can be done to enhance fixation?
Agitation of the sx
What is the result of increasing the temp (as w/ all chemical rxns)?
The speed of fixation is increased
What is the limit of increasing the temp (in terms of fixation)?
The tissue should not be cooked
True or False
Hot formalin will fix tissues slower
False, because hot formalin will fix tissues faster
What is often the 1st step on an automated tissue processor?
Using hot formalin for fixing tissues
What should be done to the concentration of fixative that will be used?
It should be adjusted to the lowest lvl possible
Why should the concentration of the fixative be adjusted down to the lowest lvl possible?
Because you will expend less money for the fixative
At what percent of concentration is formalin best?
10%
What is the range of percentage of concentration where glutaraldehyde is best at?
0.25% - 4%
What are the effects if the fixative used is present at a too high concentration?
1) Fixatives w/ too high concentration may adversely affect the tissues
2) Artefacts will be produced (similar if excessive heat is present)
Is time interval very impt also?
Yes
What is being pertained in time interval?
It is the time interval from removal of tissues to fixation
True or False
The faster you can get the tissue and fix it, the better
True
If tissue is left out, what should be done?
Artefacts will be introduced due to drying
As a resolution to tissues being dry if fixation is not done promptly, what should be done?
The tissue should be kept moist w/ saline
What are the effects if the tissue is not present in fixative for a long period of time?
1) More cellular organelles will be lost
2) More nuclear shrinkage is present
3) Artifactual clumping will occur
What is present along w/ the sxs received in the surgical path?
A request form
What are the components present in the request form?
1) Pt info
2) History
3) Description of the site of origin
How is sx accessioning done?
The sxs are accessioned by giving them a sp. # that will identify each sx for each pt
What should be done to acquire easy recognition of the sx, reduction of identification errors, and to acquire orderly storage & retrieval?
Redundancy of info
What are the 3 types of fees present in the histopath lab?
1) Processing fee
2) Professional fee
3) Hospital fee
Processing fee is based on what?
Sx size
What are the possible sizes of the sx that will be processed?
1) Small
2) Medium
3) Large
4) Radical
Professional fee is based on what?
1) Type of sx
2) If service provided or done is either diagnostic or confirmatory
3) Room rate
