HISTOPATHOLOGY Flashcards
Process
RECEIVING > NUMBERING > LOGBOOK
NAME & AGE OF PATIENT
ATTENDING PHYSICIAN
INITIAL DIAGNOSIS
TYPE OF SPECIMEN
> PATHOLOGIST: GROSSS EXAM (COLOR, CONSISTENCY, GROSS WEIGHT) > DISSECTION > TISSUE CASETTES
MEASURE > CUTTING > MEDTECH: PROCESS
Occurs once fixative penetrates the tissues
FIXATION
Primary Goal of Fixation:
TO PRESERVE TISSUES AS CLOSE TO THE ORIGINAL AS POSSIBLE
Secondary Goals of Fixation:
- TO HARDEN SPECIMEN TO FACILITATE EASY CUTTING INTO THIN SLICES
- TO PROTECT TISSUE FROM TRAUMA OF FURTHER HANDLING
Factors Involves in Fixation:
- THICKNESS/SIZE
- pH OF FIXATIVE
- OSMOLALITY
- CONCENTRATION OF FIXATIVE
- CORRECT VOLUME
- TIME AND DURATION OF FIXATION
- TEMPERATURE
Thicker = ___ fixation time
LONGER
Required size of tissue in fixation
3 x 2 cm
Required thickness of tissue in fixation
3-5 mm
Thickness of lungs tissue in fixation
1-2 cm
Ideal pH of fixative
6-8
Osmolality: by the book
SLIGHTLY HYPERTONIC
Osmolality: in practice
ISOTONIC
Osmolality: cell swelling
HYPOTONIC
Osmolality: cell shrinkage
HYPERTONIC
Concentrated solution = ___
DAMAGING
-We dilute to produce 10% solution
10% FORMALIN
Need to dilute
GLUTARALDEHYDE
Penetration rate of formalin
1 mm/hr
Maximum effective fixation
20x THE VOLUME OF SPECIMEN
Osmium tetroxide
5-10x THE VOLUME OF SPECIMEN
Ratio of fixative to specimen
15-20:1
Usual time and duration of fixation
24-48 HOURS
Temperature: EM & histochemistry
0-4 degC
Temperature: Autotechnicon
40 degC
Temperature: Manual
ROOM TEMPERATURE
Factors to be Considered when choosing the Right Fixative:
- URGENCY OF THE CASE / NEED FOR IMMEDIATE EXAM
- TYPE OF TISSUE TO BE PROCESSED
- TISSUE STRUCTURE TO BE STUDIED
- STAINING TECHNIQUE TO BE APPLIED
- TYPE OF SECTION TO BE MADE
Needs to use fixative that is fast-acting
URGENT BIOPSY
Commonly used bc rapid in action
FORMALIN
Brain tissues for diagnosis of rabies
CARNOY’S & ACETONE
Do not use for kidneys
BOUIN’S
Best for preserving Glycogen
PICRIC ACID FIXATIVES LIKE BRASIL’S FLUID
For enzymes (lipases & phosphatases)
Do not use for fats bc it dissolves fats
ACETONE
Routine staining
Compatible with many fixatives
H&E STAINING
Inhibit hematoxylin
OSMIUM TETROXIDE
Type of Section to be Made:
SERIAL / INDIVIDUAL
Factors that Prolong Fixation Time:
- COLD TEMPERATURE
- PRESENCE OF BLOOD & MUCUS IN THE SPECIMEN
- SIZE & THICKNESS OF SPECIMEN
- PRESENCE OF FATS
Remedy for Presence of blood & mucus in the specimen
WASH THE TISSUE WITH NSS
Remedy for Presence of fats
CUT THEM THINLY TO ENSURE RAPID ENTRY OF FIXATIVE
Factors that Accelerate Fixation:
- SIZE & THICKNESS OF TISSUE
- HEAT APPLICATION
- AGITATION