Fresh Frozen Section (F)

Question 1

Fresh frozen section is also known before as what?

Answer 1

Intraoperative consultation

Question 2

What is fresh frozen section (what is its principle)?

Answer 2

It is one of the special processing techniques w/c involves rapidly preserving tissue blocks by freezing to produce instant cessation of cellular activity thereby preventing chemical alteration of tissue constituents and displacement of cellular tissue components

Question 3

What are the 2 well-known procedures that are used back then (aside from using cryostat for fresh frozen section as of today)?

Answer 3

1) Freeze-drying

2) Freeze substitution

Question 4

What is the principle of freeze-drying?

Answer 4

It entails rapid freezing (/ quenching) and removing of H2O (/ desiccation) by a physical process from the frozen tissue block w/out using chemical fixative

Question 5

What is the time duration of the process of quenching step?

Answer 5

2 - 3 secs

Question 6

What is used in quenching step?

Answer 6

Isopentate / propane-isopentane mixture

Question 7

What is the characteristic of isopentate/propane-isopentane mixture used in quenching step?

Answer 7

It is chilled to -160 to -180 DC w/ liquid N

Question 8

What is used for / in desiccation?

Answer 8

High vacuum drying app (maintained at -30 to -40 DC)

Question 9

What is the time duration where complete desiccation occur?

Answer 9

Within 24 - 48 hrs

Question 10

What are the characteristics of freeze substitution?

Answer 10

1) It is basically similar to freeze-drying (but it does not use the vacuum drying app)
2) It is more economic > freeze-drying

Question 11

Since vacuum drying app is not used in freeze substitution, what is the process done?

Answer 11

It fixes the tissue via the use of chemicals

Question 12

What are the chemicals that can be used for fixing the tissue (via freeze substitution)?

Answer 12

1) Rossman’s fluid

2) Osmium tetroxide (in 1% acetone; for 1 - 6 days at -60 to -70 DC)

Question 13

What is the composition of Rossman’s fluid?

Answer 13

80 mL saturated picric acid (in 95% alcohol) + 185 mL formaldehyde

Question 14

What is done after fixing the tissue (in freeze substitution)?

Answer 14

Dehydration (via the use of absolute alcohol [at room temp] / in acetone [at -70 DC])

Question 15

As of today, what is the machine used for fresh frozen section?

Answer 15

Cryostat

Question 16

What are the legitimate purposes of frozen section (FS)?

Answer 16

1) To establish the presence and nature of a lesion
2) To determine the adequacy of surgical margins
3) To establish whether the tissue that is obtained contains diagnosable material or whether additional sampling is needed

Question 17

What did Juan Rosai said (in relation to FS)?

Answer 17

“The real aim of the procedure is to influence the course of the operation”

Question 18

What are the parts of cryostat?

Answer 18

1) Power
2) Light
3) Temp control
4) Chuck temp
5) Cutting action
6) Section
7) Downstroke speed
8) Upstroke speed
9) Chuck tightening lever
10) Blade
11) Blade adjusting lever
12) Mechanism lever
13) Roll bar
14) Collecting tray
15) Coarse control
16) Section thickness
17) Blade adjusting lock
18) Roll bar lever
19) Chuck
20) Blade guard

Question 19

What are the materials needed for doing FS’?

Answer 19

1) Embedding medium (OCT)

2) Freezing agent

Question 20

What should be done after obtaining the tissue (from the produced slide)?

Answer 20

Rapid fixation

Question 21

What is used for rapid fixation?

Answer 21

95% ethanol

Question 22

What will be the result if there is a delay in fixing the tissue (for FS’)?

Answer 22

There will be significant drying artifact

Question 23

What should be done after fixing the slide?

Answer 23

Staining of the sections

Question 24

What are the things that should be done after doing FS’?

Answer 24

1) Relaying the findings
2) Giving suggestions on how to proceed (done by / between pathos and clinicians)
3) Dx given verbally (/ discussed by the patho) should be transcribed verbatim (in an appropriate form)

Question 25

Who is the professional that can do the transcribing of the verbal dx given by the patho?

Answer 25

Histotech

Question 26

What should be done to the transcription done by the histotech?

Answer 26

A copy of it should be inserted into the chart

Question 27

What are the true limitations of the procedure (for FS’)?

Answer 27

1) Time
2) Limited special stains and studies
3) Lack of consultation
4) Freezing artifacts
a. Ice crystals (in edematous stroma)
b. Compression artifacts
c. Nuclear ice crystals
d. Nuclear chromatin changes (in frozen control)

Question 28

What are the avoidable limitations of the procedure (for FS’)?

Answer 28

1) Drying artifacts
2) Sampling error
3) Fat
4) Quality of section is inferior
5) Inconsistency of training and performance
6) Embedding

Question 29

What is the statement that is related w/ FS’?

Answer 29

One must know what excellence looks like and sounds like in order to begin to approximate it. In all forms of art one can only achieve excellence if they are aware of all the ways to make mistakes and are aware when they are happening