Diagnostic Techniques In Histopathology 🙂

Question 1

Different areas in pathology

Answer 1

Surgical, cyto, histo, autopsy pathology

Question 2

Another name for histopathology

Answer 2

Surgical, cellular, anatomic pathology

Question 3

Surgical pathology

Answer 3

A method of making a diagnosis on a tissue on gross(macro) or microscopic examination eg tumor from the breast

Question 4

Protocols of surgical pathology

Answer 4

It includes the request form, tissue accession(tissue processing), gross room, histopathology lab, surgical pathology report, quality control, histopathology and the law

Question 5

Specimens are received in two forms namely

Answer 5

• 10% formalin(buffered or fresh) it means the patient is still in the theatre and a frozen portion of the specimen is needed intraoperative(i.e frozen under liquid nitrogen -5°C) also called cryostat operative
• Formal saline

Question 6

Steps in tissue processing

Answer 6

• fixation
• dehydration
• clearing
• impregnation
• embedding

Question 7

What is fixation

Answer 7

The tissue is fixed in a 10% normal saline while the brain is fixed at 20% normal saline

Question 8

What is dehydration

Answer 8

It’s putting the tissue in ascending grades of alcohol i.e 70 to 90 to 95 to absolute(100) to remove the water from the tissue

Question 9

What is clearing

Answer 9

It’s clearing of the alcohol with either xylene or toulene but xylene is commonly used

Question 10

What is impregnation

Answer 10

It’s impregnating the tissue with wax

Question 11

What is embedding

Answer 11

It’s embedding with wax, it’s in this form that we section the tissue into cassettes form

Question 12

The diagnostic techniques in histopathology are

Answer 12

• light microscope
• electron microscope
• immunohistochemistry
• flocytometry
• cytogenetics analysis
• molecular pathology

Question 13

Light microscope

Answer 13

It is a basic tool used to magnify minute specimens using both the objective and eye piece lenses

Question 14

There are two types of microscope namely

Answer 14

Simple and compound microscope
(Know the differences)

Question 15

There are two types of modifications done on a light microscope which are

Answer 15

Dark field and polarizing microscope

Question 16

What is dark field or dark field illumination

Answer 16

It’s used for the examination of unstained living micro organisms such as treponema palladium (spirochetes). The light from this microscope don’t pass through the micro organisms but the periphery

Question 17

What is polarizing microscope

Answer 17

It’s used to demonstrate high birefringence, amaloids, foreign bodies, hair etc. The light passes through the micro organisms

Question 18

In the polarizing microscope, how many discs does it have

Answer 18

It has 2 namely: polarizer(below the obj), analyzer(within the tube)

Question 19

Some types of special stains are

Answer 19

Congo red stain used to detect amaloid i.e a green birefringence amaloids (deals with the rays)

High periodic acid schiff(PAS) used for highlighting carbohydrates, fungi and basement membrane. It’s used to differentiate glycogen from fungi i.e PAS diastasis

Van gieson stain used for extracellular collagen (for connective tissue)

Gieson-tricone used for extracellular collagen (for connective tissue)

Petha phosophotonsic stain used for muscle and myofilaments (connective tissue)

Acid hematoxylin for muscle and myofilaments (connective tissue)

Vel elastic stain for elastic fiber

Gordon and sweet silver staining for reticular fibers

Question 20

Special stains for identification of lipids

Answer 20

Oil redo and Sudan block

Question 21

SS for microorganisms are

Answer 21

• gram stains
• Ziehl neelsen stain for Tuberculosis bacilli
• Fite-wade stain for leprosy bacilli (modified Ziehl neelsen stain)
• grocott methanamine silver for fungi
• germsa stain for parasite
• shikata-orcein
• perls-prussian blue
• fontana-masson stain for fungi
• von kossa stain for calcium

Question 22

What does enzyme histochemistry require

Answer 22

It requires fresh specimen and place them in cryostat with liquid nitrogen at -5°C

Question 23

Electron microscopy has a diagnostic use in pathology in the following areas

Answer 23

• urinal pathology
• assist in the detection of ultra structure of tumor
• assist in subcellular study in microphages
• for research purposes

Question 24

Types of electron microscope are

Answer 24

• transmission electron microscope
• scanning electron microscope

Question 25

Transmission electron microscope is

Answer 25

A tool of choice for pathologist to study ultra structure of cell at organ level

Question 26

Scanning electron microscope

Answer 26

Provides a 3 dimensional image after scanning of the cell surface architecture

Question 27

Immunohistochemistry is

Answer 27

The application of immunologic techniques to cellular pathology. The technique is used to detect the status of antigen in the cells i.e cell membrane, nucleus, cytoplasm by binding to specific antibodies which are visualized by chromagen as brown color

Question 28

Cytogenetics is

Answer 28

It’s defined as a sequence of chromosomal alignment on the basis of size centromere and bandwidth pattern

Question 29

Molecular pathology is

Answer 29

It was initially employed for research purposes but recently has been deployed as diagnostic purposes

Question 30

What does molecular pathology do

Answer 30

They detect abnormalities at the level of DNA and RNA, it employs techniques based on recombinant technology

Question 31

Computer sympathology pros

Answer 31

• helps in billings of patients
• helps in reporting of patients
• helps in turnaround time
• helps in coding and indexing of results
• helps in research purposes
• helps in getting accreditation
• helps in storage and retrieval of lab data
• helps in saving time and space occupied by ledgers and records