Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

#3 Surg > 36 - Surgical Pathology > Flashcards

36 - Surgical Pathology Flashcards

1
Q

Definition of surgical pathology

A
  • Surgical pathology is the study of tissues removed from living patients during surgery to determine diagnosis and help treatment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Purpose of surgical pathology

A
  • Examine all tissues and foreign objects removed from living patients
  • Practice of surgical pathologists
  • Pathological diagnosis: “Gold standard in diagnosis ”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Examinations in surgical pathology

A

The routine work associated with a surgical pathology specimen includes two examinations:
o Gross examination
o Microscopic examination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gross examination

A
  • Gross examinations give an idea about size and shape of specimen
  • Also any gross abnormality like ulceration, nodularity, etc.
  • Gross description as well as selection of sections for microscopic study is a crucial part of pathologic examinations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Specimen collection in surgical pathology

A
  • Incisional biopsy: for diagnosis
  • Excisional biopsy: for diagnosis as well as treatment
  • Tissue collection by instruments: such as needle biopsy, core biopsy, punch biopsy, endoscopic biopsy for diagnosis
  • Organs from OR: for diagnosis as well as treatment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Surgical analysis methods (3)

A
  • Paraffin embedding method ( the routine & widely used procedure)
  • Frozen section (intra-operative) - NOT ALWAYS ACCURATE* ONLY IN EMERGENCY*
  • Cytological diagnosis (exfoliative & fine needle aspiration cytology)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

General rules for biopsy

A
  • Avoid necrosis and hemorrhage areas
  • The larger the lesion - more numerous biopsies
  • Ulcerated tumor –peripheral biopsy is suggested
  • All fragments should be collected
  • Do not crush, squeeze or do cautery
  • Fix in fixatives ASAP if it is for paraffin sectioning
  • Orientating specimen e.g. deep margin, superior and inferior margins by using sutured threads (long, short)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Containers for specimen

A
  • Size should be corresponding to specimen volume
  • Lid, which needs to be leak-proof
  • Wide mouth, flat bottom = PREFERRED***
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

** FIXATION OF THE TISSUE **

EXAM QUESTION

A
  • KNOW THIS FOR TEST QUESTION
  • Penetration rate varies a lot depending on consistency of the tissue: around 1 mm/hr
  • Compared to soft tissue, Hard tissues need more time to be thoroughly fixed
  • 10 times volume of fixative over the specimen volume should be used**
  • Minimum of 10 (10-20 ideal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Neutral buffered formalin

**EXAM QUESTION*****

A

Neutral buffered formalin - fixation time 12-24 hours.
o Formalin (40% aqueous solution of formaldehyde) - 100ml KNOW THIS FOR THE EXAM ***
o Sodium dihydrogen orthophosphate (monohydrate) - 4g
o Disodium hydrogen orthophosphate (anhydrous) - 6.5g
o Distilled water - 900ml

This fixative is suitable for most histological purposes

NOTE: since we take 40% aqueous solution of formaldehyde and mix it with 900 ml of distilled water, the FINAL CONCENTRATION OF FORMALDEHYDE IN FORMALIN IS 4%**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Further information regarding fixatives

A
  • Purpose: to preserve the tissue
  • Other fixatives include Zenker’s solution, picric acid and Bouin’s solution.
  • The best fixative is 10% neutral buffered formalin***
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Advantages of formalin

A
  • Satisfactory penetration into tissue
  • Little shrinkage
  • Very economic (cheap)
  • Satisfactory hardening
  • Preserve fat & RBC well
  • Special stains can be used on tissues after fixation
  • Preserve color of the tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Disadvantages of formalin

A
  • It needs to be changed every 3-6 months – formic acid will form, which affects tissue stainability
  • **Cannot preserve glycogen**
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Other information about formalin

*TEST QUESTION

A
  • Para-formaldehyde may form (white precipitate) when formalin solution is stored for long periods of time (years)
  • Para-formaldehyde does NOT affect the efficiency of formalin as a fixative – not a big deal
  • Para-formaldehyde can be removed by alcohol*******
    o THIS IS IMPORTANT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Procedures for parrafin section

A
    1. Fixation: with formalin
    1. Dehydration: by using gradient concentrations of alcohol (75%, 95%,100%) - For larger tissue, you NEED to do dehydration, for smaller tissues, it is recommended but not necessary
    1. Clearing: by using the flammable xylene
    1. Paraffin impregnation: fill throughout with paraffin)
    1. Embedding: to make the tissue as a block of hard paraffin
    1. Sectioning: tissue is cut into very thin section (5-8 um) in thickness by using a microtome (5 um is ideal, but 8 is still okay)
    1. Attachment: Attaching thin sections to the slides (positively charged)
    1. Dewax (de-paraffinization):-dissolve paraffin by using xylene
    1. Staining: H & E staining is the standard method which stain the nucleus blue (basophilic) & the cytoplasm pink-red (acidophilic)
    1. Mounting: apply mounting media (Permount) & cover slip on the slides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

H & E staining

A
  • In H & E staining, the nucleus blue (basophilic) & the cytoplasm pink-red (acidophilic)
17
Q

Frozen section

A
  • Frozen section is NOT a permanent section, ONLY utilized for intraoperative consultation
  • Fresh tissue is immediately frozen in liquid N2 (-196° C) made into thin section by using cryostat
  • Cryostat is a machine where you place the microtome in freezing cabinet, cut the frozen tissue
18
Q

Indications for frozen section

A
  • Benign or malignant lesions
  • Metastatic lymph node : such as sentinel nodes in breast carcinoma
  • ¬Adequacy of surgical margins (make sure you got all the malignancy)
  • Presence or absence of ganglion cells in large intestinal wall of Hirschsprung disease
19
Q

Diagnosis of frozen section

A
  • Benign vs malignant, NOT specific diagnosis

- In case of doubt, wait for permanent section

20
Q

Specimens for frozen section

A
  • Must be fresh tissues

- Small size of tissue (

21
Q

Inappropriate specimens for frozen section

*EXAM QUESTION

A

KNOW THIS SLIDE – HE PUT IT IN RED ***

  • ***Thyroid tissue (thyroid follicular lesions are difficult to determine benign vs malignant)
  • Large specimens including large tumors
  • Highly infectious specimens: HIV (due to risk of contamination)
  • TB (same thing as HIV – highly infectious, high risk of contamination)
22
Q 
-	You are seeing 4 patients with your resident. These 4 patients present in the clinic because of a mass. Each patient prefers to know if the mass is a malignant tumor or not as soon as possible. Frozen section after biopsy is the quickest way to answer this question. Which of the following specimens is least possible for frozen sectioning?
o	Single kidney mass
o	Single prostate mass
o	Single hard lymph node in the neck
o	Single thyroid mass
A

Answer = single thyroid mass

#3 Surg (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions