MLSP: HISTOPATHOLOGY SECTION Flashcards
involves different procedures that have been adopted for the preparation of materials and tissue for microscopic examination
Histopathologic Techniques
12 steps in Histopathologic Techniques:
- Numbering
- Fixation
- Dehydration
- Clearing
- Wax impregnation
- Embedding
- Blocking
- Trimming
- Sectioning
- Staining
- Mounting
- Labelling
(t or f)
o There is a 13th step which is decalcification (done or placed in between fixation and dehydration; for
bones including teeth)
o All in all, it will take 24-48 hours to do
true
• Validates if the specimen is adequate or good for
tissue processing
• 1st person that will receive the specimen and put it
into the container
RECEPTIONIST
- Proportional to the size of the specimen [larger
than the organ; the organ or specimen should
be fully submerged]
Container: contain fixatives
(t or f)
Container: contain fixatives
o If the specimen is the lungs, wrap it in gauze pads to ensure that the air inside of it wouldn’t let the organ float, hindering it to submerged fully to the
fixative agent
true
Container: contain fixatives
[to see the organ]
clear
Container: contain fixatives
[no leaking]
Unbreakable
Container: contain fixatives
[easy access]
Wide mouthed bottle
(t or f)
• The receptionist must not accept specimens that
are only placed in plastic
• Medical Technologists assist pathologists in
autopsies.
true
(t or f)
- Portion of the specimen will be placed in tissue
cassettes and the rest of the organ will be
contained
o Its shelf life is 1 year or so depending on
the policy of the hospital
true
• Specimen Source:
- Bilateral organs
o Examples: Extremities, kidneys, lungs
and ovaries) - Miscellaneous
o Examples: age, sex, ward
• Basic information needed:
1. Date and time
2. Name of the patient
3. Specimen Number
- C- Cytology specimen
- A- Anatomical specimen
- S- Surgical specimen
o Example: S-09-2111
NUMBERING
Most critical step in histopathological techniques
- If you mess this step, you will mess up everything
FIXATION
FIXATION
preserve the morphology and chemical constituents of the tissue [tissue should be alive as possible]
Primary aim
FIXATION
protect and harden the specimen for further handling
Secondary aim
TYPES OF FIXATIVES
ACCORDING TO ACTIONS
Microanatomic Fixative
Cytological Fixative
Histochemical Fixative
TYPES OF FIXATIVES
ACCORDING TO COMPOSITION
Simple Fixative
Compound Fixative
Involves small tissue or organ
- 10% Formol Saline
- 10% Neutral Buffered Formalin [tinitimpla]
Microanatomic Fixative
Involves body fluid or secretion
- Nuclear fixatives: Flemming’s Fluid, Bouin’s Fluid,
Heidehain’s Susa
- Cytopplasmic Fixatives: Kelly’s Fluid, Orth’s Fluid
Cytological Fixative
Involves tissue containing labile substances
- 10% Fomol Saline
- Absolute Ethyl Alcohol
- Acetone
Histochemical Fixative
Uses only on chemical for
fixation
- Aldehydes: Formaldehyde, Glutaraldehyde
- Metallic Fixative: Mercuric Chloride, Chromate Fixatives, Lead Fixatives
Simple Fixative
The use of two or more chemicals for fixation
Compound Fixative
• Utilizing chemical known as
dehydrating agents
• Removing of intracellular and extracellular water
and fixatives in the tissue
DEHYDRATION
DEHYDRATION
examples:
-Alcohol
- Acetone
- Dioxane
- Tetrahydrofuran
- Cellosolve (Ethylene glycol monoethyl ether)
• Removing of dehydrating agents
• Xylene – most commonly used [organic solvents]
CLEARNING
Also known as INFILTRATION OR WAX IMPREGNATION
IMPREGNATION
• The process whereby the clearing agent is
completely removed from the tissue and replace by
a medium that will completely fill all the tissue
cavities.
IMPREGNATION
the simplest, most common and best embedding medium used for routine tissue processing
- Surface area of the tissue is larger; clearing
agent is removed; specimen is further hardene
PARAFFIN WAX IMPREGNATION
Also known as CASTING OR BLOCKING
EMBEDDING
• The process by which the impregnated tissue is
placed into a precisely arrange position in a mold
containing medium which is then allowed to solidify
o Larger surface area of wax or tissue block;
larger piece to hold
EMBEDDING
• FOUR TYPES OF TISSUE IMPREGNATION:
- Parrafin wax
- Celloidin
- Gelatin
- Plastic
• Allows the medium to solidify to produce tissue
block [inaayos yung shape]
BLOCKING
• Process of removing excess wax after embedding
• Can use knife/blade or heated spatula
TRIMMING
• Also known as CUTTING OR MICROTOMY
• The process by which processed tissue is cut into
uniformly thin slices to facilitate studies under
microscope
o Making tissue ribbons [very thin segments
of wax and tissue]
SECTIONING
machine or instrument used for
cutting sections of tissue
- Blade and holder
- Thin slices; cannot do manually
- In this step, you will see the flaws and mistakes
you’ve made throughout the process
MICROTOME
KINDS OF MICROTOME
- Simplest and oldest type of microtome
Rocking Microtome
KINDS OF MICROTOME
- for cutting serial sections of tissue specimen
[common]
Rotary Microtome
KINDS OF MICROTOME
- Most dangerous type of microtome
Sliding Microtome
KINDS OF MICROTOME
- For urgent surgical biopsies specimen
Freezing Microtome
KINDS OF MICROTOME
- Permits rapid penetration of tissue biopsies for
surgical pathology - Also known as COLD MICROTOME
Rotary Microtome
KINDS OF MICROTOME
- Specimen for electron microscope
Ultrathin Microtome
• Tissue constituent are demonstrated in sections by
direct interaction with dye or staining solution
producing coloration of the active tissue
component
STAINING
- Utilizes micro-anatomical studies of tissue
- It is a regressive staining method
- Haematoxylin is used to stain nuclear
components - Eosin is used for cytoplasmic components
- Can be used as a pair
HAEMATOXYLIN AND EOSIN STAINING
the solution in which the specimen is embedded, generally under a cover glass.
o Adhesive agent to protect the specimen
MOUNTING MEDIUM
• It may be liquid, gum or resinous, soluble in water,
alcohol or other solvents and be sealed from the
external atmosphere by non- soluble ringing media
o Sealed to ensure that no dust or insect can
pass through the slide
o Indefinite shelf life
MOUNTING
• Date and time
• Name of the patient
• Specimen Number
- C- Cytology specimen
- A- Anatomical specimen
- S- Surgical specimen
o Example: S-09-2111
LABELLING
SPECIMENS FOR EXAMINATION
• Performed regularly even in pregnant women
without undue risk
• EXAMPLE: Vaginal smear
GYNECOLOGICAL SPECIMEN
SPECIMENS FOR EXAMINATION
• EXAMPLE: Respiratory Tract specimens:
- Sputum
- Bronchoalveolar lavage (BAL)
NON-GYNECOLOGICAL SPECIMEN
SPECIMENS FOR EXAMINATION
• Determine the presence of urethral cancer
- Pattern called “ferning”
URINE
