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histopathology and cytologic techniques (laboratory) > Histopathologic Techniques (M) > Flashcards

Histopathologic Techniques (M) Flashcards

1
Q

The histopathology section is concerned w/ what?

A

It is concerned w/ the dx of abnormalities within tissues and cells by microscopic examination

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2
Q

What are the meanings of the ff Greek words w/c are the origin of the term “histopathology”:

1) “HISTOS”
2) “PATHOS”
3) “LOGOS”

A

1) Tissues
2) Suffering / diseases
3) Study of

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3
Q

What is histology?

A

It is the microscopic study of normal tissues of the body

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4
Q

What is histopathology?

A

It is the microscopic study of tissues affected by disease

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5
Q

What are histologic or histopathologic techniques?

A

These are the procedures adopted for the preparation of material for such studies

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6
Q

What are the usual procedures on obtaining tissues for examination?

A

1) Surgery
2) Biopsy
3) Autopsy

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7
Q

The tissues obtained for examination range in what (in terms of size)?

A

From very large sxs or whole organs to tiny fragments of tissue

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8
Q

What are the surgical procedures that are usually performed to obtain sp type of tissue that are submitted to a histology lab for processing (/ what are the procedures for examining fresh tissue)?

A

1) Fine needle aspiration (FNAB)
2) Core needle biopsy
3) Incisional biopsy
4) Excisional biopsy
5) Punch biopsy
6) Shave biopsy

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9
Q

What are the characteristics of FNAB?

A

1) It is the simplest procedure

2) It is the least invasive test

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10
Q

What / how is FNAB done (explain its principle) and what is the cons of this procedure?

A

The smallest needle is used to simply remove cells from the area of abnormality

However, this is not always adequate to obtain a dx, depending on the area to be biopsied

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11
Q

How is core needle biopsy done (explain its principle)?

A

It removes not only cells, but also a small amt of the surrounding tissue

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12
Q

What is the pros of core needle biopsy?

A

It provides additional info to assist in examination of the lesion

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13
Q

How is incisional biopsy done (explain its principle)?

A

This procedure takes out even more surrounding tissue. It takes out some of the abnormality, but not all. The doctor will slice into the lesion and remove only a portion of it

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14
Q

If after the conduction of incisional biopsy, the lesion obtained is found to be cancerous, what should / may be done?

A

Further surgery may be needed to remove or excise the entire lesion

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15
Q

How is excisional biopsy done (explain its principle)?

A

In this procedure, the entire area in question is generally removed

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16
Q

What are the characteristics of punch biopsy?

A

1) It is considered as the primary technique for obtaining full diagnostic full-thickness sxs
2) It is easy to learn

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17
Q

What are the requirements for the lab professional that will do punch biopsy?

A

The procedure requires basic general surgical and suture-tying skills

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18
Q

How is punch biopsy done (explain its principle)?

A

It involves the use of a circular blade that is rotated down through the epidermis and dermis, and into the subcutaneous fat, yielding a 3 - 4 mm cylindrical core of tissue sx

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19
Q

How is shave biopsy done (explain its principle)?

A

It is the procedure where small fragments of tissue are “shaved” from a surface

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20
Q

At what surface (/ part of the body) is shave biopsy usually done?

A

Skin

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21
Q

Sxs are usually received in the presence of what?

A

Fixative (/ preservative)

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22
Q

Can sxs sometimes arrive fresh in the histopath lab?

A

Yes

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23
Q

What should be done to fresh sxs once they arrived (/ received) in the lab?

A

These must be immediately fixed

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24
Q

What should be present along w/ the tissue sxs received in the surgical pathology lab?

A

These should have a request form

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25
Q

What should be listed in the request form (w/c should come along the tissue sxs)?

A

1) Pt info
2) Clinical history
3) Description of the site of origin

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26
Q

What should be done to sxs that will serve as their label?

A

The sxs are accessioned by giving them a number that will identify each sx for each pt

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27
Q

What is impt to be done to minimize the risk of mislabeling?

A

It is impt that sxs are properly identified

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28
Q

Methods of tissue examination may vary accdg to what?

A

Structural and chemical components of the cells to be studied

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29
Q

Methods of tissue examination depends on what?

A

Nature and amt of tissue to be evaluated

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30
Q

Fresh tissues are usually examined in what circumstance?

A

When there is a need for evaluation

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31
Q

What is the better and more effective means of studying tissues (whether normal or abnormal)?

A

By examination of adequately preserved sections and smears that are stained to demonstrate sp structures

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32
Q

What should be done to glass slides for permanent keeping?

A

These should be mounted w/ coverslips for permanent keeping

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33
Q

True or False

Examination may be done on fresh or preserved tissues depending on necessity

A

True

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34
Q

What are the advantages of examining fresh tissues?

A

1) These tissues can be examined in the living state

2) Since these tissues can be examined in the living state, protoplasmic activities can be observed

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35
Q

What are the exs of protoplasmic activities w/c are done by fresh tissues?

A

1) Motion
2) Mitosis
3) Phagocytosis

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36
Q

What is the disadvantage of examining fresh tissues?

A

Since these tissues are examined in the fresh state w/c is not permanent, this is the reason / is liable to develop the changes that have usually been observed after death

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37
Q

What are the methods for fresh tissue examination?

A

1) Teasing or Dissociation
2) Squash Preparation (Crushing)
3) Smear Preparation
a. Streaking
b. Spreading
c. Pull-Apart
4) Touch Preparation (Impression Smear)

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38
Q

What is the process (/ steps) of teasing?

A

1) A selected tissue sx is immersed in isotonic solution (such as normal saline or Ringer’s solution) in a petri dish or watch glass
2) It is carefully dissected w/ a needle and separated by direct or zigzag spread using an applicator stick
3) Selected pieces of the tissue are transferred carefully to a microscope slide and mounted as a wet preparation underneath a cover glass
- > care being taken to avoid the formation of bubbles
4) It is either stained w/ a supravital dye or examined unstained by phase contrast or bright field microscopy

The preparations are not permanent

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39
Q

What is the advantage of the application of teasing as a method of fresh tissue examination?

A

The procedure has the advantage of permitting the cells to be examined in the living state

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40
Q

What is the result (/ benefit) of using phase contrast microscope in terms of the examination of fresh tissue?

A

The use of phase contrast microscope greatly increases the structural detail of the cells examined in the living state w/c allows movement and mitotic division to be observed

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41
Q

What stain can be used in teasing?

A

Methylene blue

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42
Q

What is the process (/ principle) of squash preparation?

A

Small pcs of tissue are placed in the microscopic slide and forcibly compressed w/ another slide or w/ a cover glass

If necessary, a supravital stain may be placed at the junction of the slide and the cover glass, and allow to be absorbed by the tissue through capillary action

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43
Q

What should be the size (in diameter; in mm) of the tissue that will be used in squash preparation?

A

Not 1 mm >

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44
Q

The method of preparing the smears differs depending on what?

A

Depending on the nature of the material to be examined

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45
Q

What is the general rule (/ procedure) for smear preparation?

A

Smears are made either by spreading the selected portion of the sx over the surface of the slide w/ a platinum loop

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46
Q

What is the alternative way of making / preparing smears?

A

An apposition smear can be made using a 2nd slide to obtain a relatively uniform distribution of secretion

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47
Q

What should be done when preparing smears?

A

Avoid making too thin / too thick smears

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48
Q

Why are too thin or too thick smears should be avoided?

A

Because they make the tissues less suitable for examination

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49
Q

True or False

Smears may be examined either as fresh preparations similar to that described for teased preparations, or by using a supravital staining technique

A

True

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50
Q

How can smears be made permanent?

A

Smear preparations can be made permanent by fixing them while still wet

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51
Q

What is the importance of staining smear preparations?

A

To demonstrate sp structures and inclusions

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52
Q

True or False

The cleared sx (in smear prep) should be mounted beneath a cover glass w/ the use of a suitable mounting medium

A

True

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53
Q

The procedure of smear preparation is useful for preparing smears of what?

A

Thick secretions such as:

1) Serous fluids
2) Concentrated sputum
3) Enzymatic lavage sxs from the GIT
4) Blood smears

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54
Q

The technique of smear preparation is especially useful in what?

A

Cytological examinations, particularly for cancer dx

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55
Q

What is the process of streaking (as a type of smear prep)?

A

With an applicator stick or a platinum loop, the material is rapidly and gently applied in a direct or zigzag line throughout the slide, attempting to obtain a relatively uniform distribution of secretion

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56
Q

What should be avoided when streaking?

A

The formation of too thin or too thick smears

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57
Q

Why should the formation of too thin / too thick smears be avoided (in streaking)?

A

Because they make tissues unsuitable for examination

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58
Q

How is spreading done?

A

A selected portion of the material is transferred to a clean slide and gently spread into a moderately thick film by teasing the mucous strands apart with an applicator stick

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59
Q

What is the comparison between the process of streaking and spreading?

A

The process of spreading is a little more tedious > streaking

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60
Q

What is the advantage brought by spreading?

A

It has the advantage of maintaining cellular interrelationships of the material to be examined

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61
Q

Spreading is especially recommended for smear preparations of what?

A

1) Fresh sputum
2) Bronchial aspirates
3) Thick mucoid secretions

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62
Q

How is pull-apart (w/c is a type of smear prep) done (explain its principle)?

A

1) This is done by placing a drop of secretion or sediment upon one slide and facing it to another clean slide
2) The material disperses evenly over the surface of the two slides
3) Slight movement of the two slides in opposite directions may be necessary to initiate the flow of
materials
4) The two slides are then pulled apart with a single uninterrupted motion, and the specimen is placed under the microscope for immediate examination, or applied with vital stains

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63
Q

What is the characteristic of touch preparation?

A

This is a special method of smear preparation

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64
Q

How is touch preparation done?

A

The surface of a freshly cut piece of tissue is brought into contact and pressed on to the surface of a clean glass slide, allowing the cells to be transferred directly to the slide for examination by Phase Contrast microscopy or staining for light microscopic study

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65
Q

What is the advantage brought by touch preparation?

A

The cells may be examined w/out destroying their intercellular relationship

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66
Q

In order to enable the patho to diagnose the presence / absence of disease, what is needed to be done by the histotechnologist?

A

The histotechnologist needs to produce a tissue section of good quality

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67
Q

Why should the histotechnologist need to produce a tissue section of good quality?

A

Because this allows for adequate interpretation of microscopic cellular changes

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68
Q

What are needed to be done to solid tissues?

A

These are needed to be fixed and processed

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69
Q

Why is it needed to fix and process solid tissues?

A

To preserve the structures of these tissues

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70
Q

After fixing and processing the solid tissues, what should be done?

A

These tissues should be impregnated w/ an appropriate hardening substance

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71
Q

Why should solid tissues be impregnated w/ an appropriate hardening substance?

A

To permit making thin slices suitable for staining and microscopic evaluation

72
Q

What is the process (/ steps) of processing tissue for paraffin sections?

A

1) Fixation
2) Decalcification (optional)
3) Dehydration
4) Clearing
5) Impregnation (Infiltration)
6) Embedding
7) Trimming
8) Section-Cutting (Microtomy)
9) Staining
10) Mounting
11) Labeling

73
Q

True or False

It is not important that tissues are handled carefully and appropriately fixed as soon as possible after arriving in the lab

A

False, because it is important that tissues are handled carefully and appropriately fixed as soon as possible after arriving in the lab

74
Q

What is the done in fixation step?

A

The sx is placed in a liquid fixing agent (fixative)

75
Q

What is the fixative used for fixing the sx?

A

Formaldehyde solution (/ formalin)

76
Q

What is the action of formalin?

A

It will slowly penetrate the tissue causing chemical and physical changes that will harden and preserve the tissue and protect it against subsequent processing steps

77
Q

What type of solution is formalin?

A

It is usually a phosphate-buffered solution

78
Q

What is the most popular fixative for preserving tissues that will be processed for paraffin embedding?

A

Formalin

79
Q

Is it needed for sxs to remain in fixative long enough?

A

Yes

80
Q

Why should the sxs remain in fixative long enough (/ for a long period of time)?

A

For it to penetrate the tissue

81
Q

Is it needed for sxs to remain another additional period (after a long period of time) in fixative?

A

Yes

82
Q

Why is it needed for sxs to remain another additional period (after a long period of time) in fixative?

A

In order to allow the chemical rxns of fixation to reach equilibrium (fixation time)

83
Q

What is the characteristic of fixation step?

A

It is a critical step in the preparation of histological sections

84
Q

What is the result if fixation is not carried out under optimal conditions or if fixation is delayed?

A

It can result to a tissue sx that is irreversibly damaged

85
Q

After fixation, what should be done?

A

The appropriately trimmed sxs are placed in suitable labelled cassettes (small perforated baskets)

86
Q

Why should appropriately trimmed sxs be placed in suitable labelled cassettes?

A

To segregate these sxs from other sxs

87
Q

True or False

Formalin-fixed, paraffin-embedded tissues may be stored indefinitely at body temp

A

False, because formalin-fixed, paraffin-embedded tissues may be stored indefinitely at room temp

88
Q

True or False

Nucleic acids (both DNA and RNA) may not be recovered from formalin-fixed, paraffin-embedded tissues decades after fixation

A

False, because nucleic acids (both DNA and RNA) may be recovered from formalin-fixed, paraffin-embedded tissues decades after fixation

89
Q

What is the characteristic of melted paraffin wax?

A

It is hydrophobic (not miscible w/ H2O)

90
Q

What is the result due to the characteristic of melted paraffin wax?

A

Most of the H2O in a sx must be removed before it can be infiltrated w/ wax

91
Q

What is the principle of the process of dehydration?

A

This process is commonly carried out by immersing the sxs in a series of ethanol (alcohol) solutions w/ increasing concentration

92
Q

What is the reason behind the principle of dehydration?

A

To avoid excessive distortion of tissue until a- free tissue in alcohol is reached

93
Q

What happens to H2O soluble proteins when exposed at lower concentrations of ethanol?

A

These are removed

94
Q

What happens when ethanol concentration is increased to 100%?

A

H2O certain lipids may be dissolved

95
Q

What is the typical dehydration sequence for sxs not 4 mm > thick?

A

1) 70% ethanol for 15 mins
2) 90% ethanol for 15 mins
3) 100% ethanol for 15 mins
4) 100% ethanol for 15 mins
5) 100 % ethanol for 30 mins
6) 100% ethanol for 45 mins

96
Q

True or False

Fatty tissues may be inadequately processed in what is normally a successful schedule for other tissues

A

True

97
Q

What are the exs of fatty tissues?

A

1) Breast

2) Lipoma

98
Q

What is the characteristic of ethanol?

A

It is a poor fat solvent

99
Q

What should be done to ensure complete dehydration?

A

A superior fat solvent should be added before the final absolute ethanol and chloroform or trichloroethane used as the transition solvent

100
Q

What are the exs of superior fat solvent?

A

1) Acetone

2) Isopropanol

101
Q

What is the process of clearing step?

A

The dehydrated tissue is transferred to an intermediate solvent that is fully miscible with both ethanol and paraffin wax

102
Q

Why is the term “clearing” used?

A

Because many (but not all) clearing agents impart an optical clarity or transparency to the tissue due to their relatively high refractive index

103
Q

What is the impt role of the clearing agent?

A

To remove substantial amt of fat from the tissue w/c otherwise presents a barrier to wax infiltration

104
Q

What is done after dehydration?

A

The tissue is immersed in 1 - 3 different xylene immersions. In these stages, the ethanol is gradually replaced w/ xylene and when the tissue is embedded, the xylene will then be replaced by the molten paraffin wax

105
Q

What is the typical clearing sequence for sxs that are not 4 mm > thick?

A

1) Xylene for 20 mins
2) Xylene for 20 mins
3) Xylene for 45 mins

106
Q

What is the process of infiltration step?

A

The cleared tissue is infiltrated w/ a suitable histological wax (usually paraffin) which is liquid at 60°C and then allowed to cool to 20°C in order to solidify into a consistency that allows sections to be cut

107
Q

The waxes (/ histological wax) are mixtures of what?

A

Mixtures of purified paraffin wax and various additives that may include resins

108
Q

What are the exs of resins?

A

1) Styrene

2) Polyethylene

109
Q

What is the benefit of using resins (w/c are part of the mixture of the waxes / histological wax?

A

The usage of these resins allow them to be sectioned thin enough on a microtome, forming ribbons that can flatten fully when floated on a warm H2O bath. To completely displace the clearing agent

110
Q

What is the typical paraffin infiltration sequence of paraffin for sxs that are not 4 mm > thick?

A

1) Paraffin wax for 30 mins
2) Paraffin wax for 30 mins
3) Paraffin wax for 45 mins

111
Q

What is the process of embedding step?

A

Once the tissue has been processed it is ready to be oriented into a paraffin block and subsequently sectioned. After infiltration with wax, the tissue is oriented and placed in a mold that is filled with molten wax to form a solid tissue block that can later be clamped into a microtome for sectioning. The infiltrated tissue is removed from the cassette and very carefully oriented in a suitably sized metal mold so that the “plane of section” can be determined

Usually tissues are embedded with the surface to be cut facing down in the mold. After orienting the section, the mold is filled with molten wax. The main part of the labelled cassette is placed on top of the mold and topped up with more wax. The whole mold is placed on a cold plate to solidify. When this is completed the block with its attached cassette can be removed from the mold and is ready to be sectioned on a microtome

112
Q

What is the most impt step in embedding?

A

Correct orientation of tissue in a mold

113
Q

What is the result of incorrect placement of tissues?

A

It may result in diagnostically impt tissue elements being missed or damaged during microtomy

114
Q

In embedding, the choice of mold depends on what?

A

Depends on the type of chuck in the microtome that will be used to section the tissue

115
Q

What are the different molds that can be used in embedding?

A

1) Stainless steel
2) Ceramic
3) Paper
4) Plastic
5) Aluminum foil

116
Q

Is the basic method of in connection to embedding the same across all different molds that can be used in embedding?

A

Yes

117
Q

What is double embedding (explain its principle)?

A

It is the process by w/c tissues are 1st embedded or fully infiltrated w/ a supporting medium, then infiltrated a 2nd time w/ wax in w/c they are also embedded

118
Q

What are the exs of supporting medium that is used to fully infiltrate the tissues (in embedding)?

A

1) Agar

2) Nitrocellulose

119
Q

What are the characteristics of double embedding in agar-paraffin?

A

It is a reliable and convenient method of handling minute and friable tissue fragments such as curetting and endoscopic biopsies, w/c can be lost during tissue processing

It also overcomes the difficulty of manipulating small tissue fragments during embedding and facilitates correct orientation and identification of tissues for histochemistry and immunohistochemistry (IHC)

120
Q

What will happen to tissues by the time they are infiltrated w/ wax?

A

The tissues may shrink

121
Q

Since the tissues may shrink by the time they are infiltrated w/ wax, but what will be the result if these are adequately processed?

A

They will still show good morphological detail and allow for accurate histopathological evaluation

122
Q

The immiscibility of most epoxy and acrylic resins w/ H2O necessitates the use of what process and what is used in this process?

A

Dehydration, usually w/ the use of ethanol

123
Q

What is a microtome and what is its mechanism?

A

It is nothing more than a knife w/ a mechanism for advancing a paraffin block across the knife

124
Q

*What are the different characteristics of knives?

A

1) These can be of the std thick metal variety

2) Or these can be thin disposable variety (like a disposable razor blade)

125
Q

*Can the distance on the microtome be set? If yes, what is its distance for most paraffin embedded tissues?

A

6 - 8 microns

126
Q

What are the exs of plastic blocks?

A

1) Methacrylate
2) Araldite
3) Epon

127
Q

What are plastic blocks?

A

These are sectioned w/ glass or diamond knives

128
Q

*What are the fxs of diamond knives?

A

1) These can cut selections down to about 1 micron

2) These can best make thin sections for electron microscopy

129
Q

What is the measurement of the thin sections (cut by a diamond knife) for electron microscopy?

A

0.25 micron

130
Q

Under section-cutting, what should be done to glass slides containing the sx?

A

These are placed in a warm oven

131
Q

What is the time duration needed for the glass slides (containing the sx) that are placed in the oven?

A

About 15 mins

132
Q

What is the purpose of placing the glass slides containing the sx in the oven for about 15 mins?

A

To help the section adhere to the slide

133
Q

If the heat omitted by the oven to the glass slides (containing the sx) might harm things such as Ags for immunostaining, what should be done (/ what is the resolution that can be done)?

A

This step can be bypassed and glue-coated slides can be used instead to pick up the sections

134
Q

True or False

It is impt to have a properly fixed and embedded block or much artifact can be introduced during the sectioning

A

True

135
Q

*Common artifacts that can be introduced during the sectioning include what?

A

1) Tearing
2) Ripping
3) Creases
4) Holes
5) Folding of sections

136
Q

What should be done once sections are cut?

A

These are floated on a warm H2O bath that helps remove wrinkles

137
Q

What should be done after letting the cut sections float on a warm H2O bath?

A

These are picked up on a glass microscopic slide

138
Q

What should be done after picking up the cut sections (that are floating on a warm H2O bath)?

A

The tissue slide is drained and may be gently heated to evaporate the layer of H2O between the sections and the glass

139
Q

What should be done after draining the tissue slide or after gently heating the tissue slide and what is the purpose of this step?

A

When all H2O is gone, the slide may be heated enough to melt the wax, a procedure that may improve adhesion

140
Q

What is the process of the step of mounting of tissue sections?

A

Paraffinized ribbons of serial tissue sections can be removed from the microtome knife as they are cut, by using a wooden tongue depressor blade. In this process, a slight traction is exerted on the end of the ribbon, stretching it gradually over the wooden blade while floating in a warm water bath. The temperature of the warm bath should be kept at 5–10 DC below the melting point of the embedding wax. If it is too hot, desiccated-looking sections will result, while cool water baths will produce excessive wrinkling of the tissue. Adding a few drops of ethyl alcohol to the water may facilitate the mounting of tissue sections. The ribbon must not be left in the bath for more than 1 or 2 minutes, or over-hydration of the tissue will be produced, simulating the appearance of edema fluid when examined microscopically

141
Q

Because tissue sections do not adhere well to untreated glass slides, what should be observed?

A

A bonding agent also must be a component of the H2O bath

142
Q

*What are the suitable additives w/c play as a bonding agent that should be present in the H2O bath?

A

1) Albumin

2) Poly-L-lysine

143
Q

What is the most serous issues faced in histotechnology?

A

Misidentification of tissues, w/c includes mislabeled sxs, block identification problems, and tissue contaminants

144
Q

What is the potentially dangerous mistake that can take place when mounting sections from flotation baths?

A

The “shedding” of friable small tissue fragments that float freely on the surface of the H2O, and w/c may be inadvertently picked up when mounting slides from subsequently processed but unrelated cases

145
Q

What are floaters?

A

These are tiny pcs of unrelated tissue w/c commonly cause problems in the interpretation of the biopsies done by the patho

146
Q

Provide an ex of how floaters can produce interference

A

A small pc of unrelated cancerous tissue may inadvertently “float” and be deposited on the slides of a subsequent case that is being evaluated for the presence of malignancy whereas this may lead to an inaccurate dx and result in medicolegal liabilities on both the patho and the histotechnologist

147
Q

What should be done to alleviate the danger or interference brought by rare contaminants that are being carried over to subsequent sections being mounted?

A

Meticulous cleaning of the microtome H2O bath and frequent clearing or changing of the H2O

Also, the technologist must routinely skim, or otherwise clear, the surface of the H2O bath between cases

148
Q

What is the another source of floater-type artefact?

A

“Tongue blade metastasis”

149
Q

*What is the principle of tongue blade metastasis and on what type of sxs does this principle apply?

A

The tissue adheres to a wooden applicator stick that is used to float successively preped ribbons from 2 different cases

These principle apply in cases where the sx is limited in size (such as skin, bronchoscopy, and gastrointestinal biosies)

150
Q

True or False

It is advisable to save any unmounted paraffin ribbon (w/ appropriate identification) from such cases for at least a week after they are accessioned, so that remounts can be prepared when additional sections are requested, w/out the need for further microtomy of the tissue block

A

True

151
Q

What is the process of staining step (explain its principle)?

A

The tissue sections mounted on the slide are nearly invisible under a light microscope so they must be stained to create contrast. After drying in a 60 DC, the slide is passed through another series of chemical reagents. Xylene removes the paraffin and absolute alcohol removes the xylene. The tissue on the slide is then rehydrated to prepare it for staining. Most staining procedures in the laboratory, aside from antibody-based immunohistochemistry (IHC), use chemicals or dyes that will bind or have affinity for certain components of the cells and extracellular components. The chemical properties of these dyes produce the visual appearance that is seen under the microscope

Potential contamination during the staining procedure may be much higher than having “floaters” when mounting sections from a water bath. The tissue is deparaffinized during the first steps in preparing the slides for staining. As the slides are dipped up and down into the staining baths, the deparaffinized tissue can fragment and small dis-cohesive pieces can break free and be lifted on the slide. Contamination in the staining solution is dependent on the volume of slides being stained and the time point during the day that the samples are taken. Because the stainer baths are a potential reservoir of tissue contaminants, changing the staining fluids may alleviate some of the potential for carryover from this source. And, as higher numbers of the contaminating fragments are localized to the first xylenes and alcohols, frequently changing these baths in particular may also be useful.

152
Q

What is the action of xylene?

A

It removes the paraffin

153
Q

What is the action of absolute alcohol?

A

It removes the xylene

154
Q

True or False

Different staining procedures are done depending on the tissue component that is being studied

A

True

155
Q

Because stainer baths are a potential reservoir of tissue contaminants, what should be done to alleviate some of the potential for carryover from this source?

A

Changing the staining fluids

156
Q

*What is the outline of the process (/ steps) of tissue processing?

A

1) Sx identification
2) Labeling
3) Grossing
4) Collection
5) Fixation

157
Q

The lab dx of an infectious disease begins w/ what?

A

It begins w/ the collection of a clinical sx for examination or processing in the lab

158
Q

What is the rule in terms of sx identification and labeling?

A

Right one, collected at the right time, transported in the right way to the right lab

159
Q

What is the 1st step to have an accurate lab dx?

A

Proper collection

160
Q

In terms of collection and transportation of sxs, what should be done?

A

A fixative should be used

161
Q

What is the purpose of using fixative in connection to collection and transportation of sxs?

A

For the prevention of contamination and autolysis of the sx

162
Q

What is the purpose of doing gross examination?

A

It is done in order to establish and to select relevant portions for microscopic examination

163
Q

True or False

Dx done is on the basis of gross examination 90% of sxs and in the remaining 10%, the skilled patho can be close to the dx

A

True

164
Q

What are the 2 mandatory prerequisites before gross examination?

A

1) Knowledge of the clinical history

2) Thorough knowledge of the anatomy of the organ

165
Q

What is gross examination?

A

It is the process by w/c pathology sxs are inspected w/ the bare eye to obtain diagnostic info while being processed for further microscopic examination

166
Q

What are the general gross parameters for surgical sxs?

A

1) Size
2) Shape
3) Consistency
4) Color
5) Weight
6) Measurement
7) General appearance

167
Q

What are the instruments used in grossing?

A

1) Large scissors
2) Dissecting scissors
3) Blade
4) Gloves
5) Scalpel
6) Saw
7) Forceps
8) Ruler
9) Cassettes
10) Cutting boards

168
Q

What are the things that should be observed in terms of selection and collection of sx?

A

1) A basic rule is that, the fewer sections are taken, the fewer slides will need to be reviewed.
2) Without delay after death/sampling and fix
3) Selected tissue should contain portion of lesion
4) Take younger lesion from periphery.
5) Take specimen from more than one areas of affected organs.
6) Cut must be made quickly, sharply and accurately.
7) Optimum thickness is 5-6 mm.
8) No pitching, squeezing, bending or crushing
9) Wash blood with normal saline

169
Q

What is the meaning TAH-BSO?

A

Total Abdominal Hysterectomy and Bilateral Salphingo-Oophorectomy

170
Q

What is the meaning of MRM?

A

Modified Radical Mastectomy

171
Q

What is the process of removal of gallbladder?

A

Laparascopic Cholecystectomy

172
Q

What is the process of removal of thyroid?

A

Total Thyroidectomy

173
Q

What is the process of removal of appendix?

A

Appendectomy

174
Q

What is the process of removal of placenta?

A

Placental expulsion

175
Q

What is the process of removal of colon?

A

Colectomy

histopathology and cytologic techniques (laboratory) (20 decks)

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