HISTECH LAB INTRO

Histology

science concerned with the microscopic

aka microanatomy

Pathology

study of disease

Histology

science concerned with the microscopic

aka microanatomy

Pathology

study of disease

Pathologist

a physician highly skilled in the identification and diagnosis of both normal and diseased tissues

Anatomic pathology

microscopic analysis of tissue changes

Clinical pathology

hema, microbio, immuno, cc, bb, lab data management

Histopathology

branch of pathology which concerns with the demo of minute structural alterations in tissues as a result of disease

Permanent sections

most convenient way to study morbid tissues

Tertiary hospital

What hospital level has a histopathology section?

Large, variably shaped nuclei

many dividing cells

disorganized arrangement

variation in size and shape

loss of normal features.

5 features of cancerous cells

Specimen accessioning
Gross examination
Tissue fixation
Tissue processing
Tissue embedding
Tissue sectioning
Slide staining

Histology procedure (7)

Dehydration
Clearing
Impregnation

3 parts of tissue processing (DCI)

Histopathology remains a neglected branch of medical
technology in the Philippines

Majority of hospital laboratories do not have basic equipment
(such as pH meter)

Most laboratories are neglected with old, obsolete, defective,
and missing apparatuses.

Inadequately - trained medical technicians and non -
paramedical personnel

Production of low quality slides given to the pathologists

5 Challenges of Histopathology in the
Philippine Setting

True

T/F

Xylene, alcohol, and formalin may be reused by investing in distillation and filtration systems

Identification of the specimen and all of its components

First step in specimen processing in histopath

Gross examination

How do pathologists examine tissue?

A process by which pathology specimens are inspected with the bare eye to obtain diagnostic information, while being processed for further microscopic examination

The specimen consists of

TSCO means:

Category A specimen

Endometrium
Breast core biopsies
Colonic series

Category B specimen

Small lipoma
Small skin biopsy
Cervical LLETZ

Category C specimen

Prepuce
Haemorrhoids
Gallbladder
Appendix

Category D specimen

Pigmented skin lesions
Large intestine (Crohn's)
Skin with markers
Salivary gland tumor

Category E specimen

Thryoid (medullary Ca)
Breast cancer
Testis (seminoma)
Uterus (endometrium Ca)

Block 3 in 1

3 types of tissues, 1 casette

Identify all hazards in and emanating from the laboratory

First step in risk management

Standard operating procedure

Control of hazardous substances
Risk assessments
Health and safety information

Microscope
Microtome
Cryostat
Autotechnicon
Automated coverslipper
Automated H&E stainer

Instrumentation in histopathology (MMCAAA)

1. Name, Manufacturer, Model Number and Serial Number
2. Record of preventive maintenance performed, as prescribed by the manufacturer
3. Record of service calls and repairs performed
4. Copy of operating manual

It is imperative that the laboratory maintain a current file for every piece of equipment in the laboratory.

This file should contain the following information: (4) (NRRC)

Read the manual that accompanies the equipment

What is the 1st and most important step in the operation of equipment?

Manual

-provides information to the machines operation

Presentation of checklist

What is the recommended step for every new employee?

Checklist

provides a step-by-step approach to the machine's operation

Small spill

defined as a spill that can be sagely handled by immediate staff

Simply wipe off with towel or sponge while protecting hands with suitable gloves.

How to handle small spills? (only a few grams or mL)

Area must be sealed off and an emergency team must be called.

How to handle large spills?

Ingestion
Eyecontact
Extensive skin contact
Splashing of dangerous chemicals into the eyes

Most common accidents requiring first aid (4)

15-30 minutes

accidental splashing of eyes how many mins to wash

15-30 minutes

accidental skin contact, how many minutes to wash?

Fresh tissue and body fluids

must always be considered potentially infectious

Grossing of specimen

has the highest risk of all histological activities

Fixed specimens

have a much less risk because of nearly all infectious agents are deactivated by histological fixation

Prions

Infectious agents that cause spongiform encephalopathies

Creutzfeld-Jakob disease
Mad cow disease

2 examples of prions

Biohazards
Corrosive chemicals
Sensitizers
Carcinogens
Toxic materials

Health hazards in the histopath section (BCSCT)

Combustibles
Flammables
Explosive chemicals
Oxidizers

Physical hazards in the histopath section (CFEO)

PELs

Permissible Exposure Limits

TLVs

Threshold Limit Values

OELs

Occupational Exposure Limits

Dangerous liquids

stored below countertop height

Dangerous reagents

Stored in plastic or plastic - coated glass bottles

Flammable liquids

• Never store in refrigerator or freezer

• If usage cannot be avoided, small amount must be available and used up asap

• Fine needle aspiration
• Core needle biopsy
• Incisional biopsy
• Excisional biopsy
• Punch biopsy
• Shave biopsy
• Curettings

Methods of fresh tissue examination (FCIEPSC)

Fine needle aspiration

is the simplest, least invasive test and uses the smallest needle to simply remove cells from the area of abnormality.

This is not always adequate to obtain a diagnosis, depending on the area to be biopsied.

Core needle biopsy

removes not only cells, but also a small amount of the surrounding tissue.

This provides additional information to assist in the examination of the lesion

Incisional and excisional biopsy

Incisional biopsy takes out even more surrounding tissue. It takes out some of the abnormality, but not all. The doctor will slice into the lesion and remove only a portion of it. If the lesion is found to be cancerous, further surgery may be needed to remove or excise the entire lesion.

Excisional biopsy generally removes the entire area in question

Punch biopsy

is considered the primary technique for obtaining diagnostic full-thickness skin specimens.

It requires basic general surgical and suture-tying skills and is easy to learn.

The technique involves the use of a circular blade that is rotated down through the epidermis and dermis, and into the subcutaneous fat, yielding a 3- to 4- mm cylindrical core of tissue sample.

Shave biopsy

where small fragments of tissue are “shaved” from a surface (usually skin).

Curettings

where tissue is scooped or spooned to remove tissue or growths from body cavity such as endometrium or cervical canal.

Teasing or dissociation

Immersed in a watch glass containing isotonic salt solution, carefully dissected or separated, and examined under the microscope

Unstained teasing

for phase contrast or bright field microscopy

Stained teasing

differential dyes

Squash preparation

Small pieces of tissue not more than 1mm in diameter are placed in a microscopic slide and forcibly compressed with another slide or with a cover slip

Smear preparation

Process of examination wherein cellular materials are spread lightly over a slide (wire loop, wire applicator, or apposition smear with another slide.)

Useful in cytological examinations particularly for cancer diagnosis

Streaking

With an applicator stick or a platinum loop, the material is rapidly and gently applied in a zigzag line throughout the slide, attempting to obtain a relatively uniform distribution of secretion.

Spreading

• A selected portion of the material is transferred to a clean slide and gently spread into a moderately thick film by teasing the mucous strands apart with an applicator stick.

• Has the advantage of maintaining cellular interrelationships of the material to be examined.

• Recommended for smear preparations of fresh sputum and bronchial aspirates and thick mucoid secretions

Pull-apart

Useful for preparing smears of thick secretions such as serous fluids, concentrated sputum, enzymatic lavage samples from the gastrointestinal tract and blood smears

Impression smear

A special method of smear preparation whereby the surface of a freshly cut piece of a clean slide, allowing the cells to be transferred directly to the slide for examination by Phase Contrast microscopy or stained for light microscopic study

Frozen section

Normally utilized when a rapid diagnosis of the tissue under question is required.

Lipids and nervous tissue elements

When is frozen section recommended?

10-15 micrometer in thickness and -10 degrees C to -20 degrees C

Frozen section are cut into very thin slices around how many micrometers in thickness and what temperature?

Slow freezing

Distortion of tissue due to ice crystal artifacts

Liquid nitrogen
Isopentane cooled by liquid nitrogen
Carbon dioxide gas
Aerosol sprays

Commonly used methods of freezing (LICA)