LESSON 1 Flashcards
preparation, processing and staining of tissue sections for
microscopic study to be interpreted by the pathologist
HISTOTECHNIQUES
study of disease at the tissue level
HISTOPATHOLOGY
examined to determine the cause of death
Autopsy Materials
otherwise referred to as surgical or biopsy materials; examined to provide
a diagnosis
Surgical Materials
removal of cells from the area of abnormality
➢ considered as the simplest and least invasive method of collecting biopsy
specimens
➢ method of collection for fluid-containing tumors
FINE NEEDLE ASPIRATION
removal of cells and small amount of surrounding tissue
CORE NEEDLE BIOSY
removal of cells with more surrounding tissue
INCISIONAL BIOPSY
removal of the entire area in question
➢ Ensure complete removal of the lesion
➢ Confirm that the diagnosis is correct
EXCISIONAL BIOPSY
removal of 3 to 4 mm cylindrical core of tissue samples
➢ small: 2mm; large: 4mm
➢ lesion should be at the center
PUNCH BIOPSY
removal of small fragments of tissue from a surface
SHAVE BIOPSY
removal of tissue or growths from body cavities
CURETTINGS
Storage of Specimen
1 month to 1 year
Storage of Tissue Blocks
3 to 10 years
Storage of Slides
Indefinite
Storage of Records (request and result forms)
Permanent
- Structural and chemical components to be studied
- Nature and amount of sample to be evaluated
- The need to provide an immediate diagnosis
FACTORS TO BE CONSIDERED IN CHOOSING A METHOD
➢ No fixative required
➢ Examined using a Brightfield or Phase-Contrast microscope
➢ Stained with supravital or differential dyes
FRESH TISSUE EXAMINATION
✓ Observation of physiologic processes or protoplasmic activities (motion, mitosis,
phagocytosis and pinocytosis)
✓ Relatively simple and easy to perform
ADVANTAGES OF FRESH TISSUE EXAMINATION
✓ Limited use
✓ Liable to develop changes observed after death (putrefaction and autolysis)
DISADVANTAGES OF FRESH TISSUE EXAMINATION
✓ Dissection or separation of tissue components in NSS or Ringer’s solution
✓ Examined as stained or unstained
✓ Anatomical relationship is destroyed
TEASING
✓ Tissue (<1mm) is sandwiched between two slides
✓ Stain is applied on one side of the slide and allowed to spread via capillary
action
SQUASH
▪ for cytological studies, especially for the diagnosis of cancer
▪ for sections or sediments
▪ performed using a wire loop, applicator stick or another slide
SMEARING
✓ Uniform distribution in a direct or zigzag manner
Smearing-Streaking
✓ Thick or mucoid specimens
✓ Teasing on a slide
✓ Maintains intercellular relationship
Smearing-Spreading
✓ For the preparation of blood and bone marrow smears
Smearing-Pull-Apart
✓ One side of a slide is allowed to touch a surface of the sample
✓ Intercellular relationship is maintained
Smearing-Touch
Preparation
✓ Prepared using freezing microtome or cryostat
✓ For rapid diagnosis
✓ For delicate specimens
FROZEN SECTION
➢ Performed by the medical technologist
➢ Check label and request form
➢ The specimen is given a label (numeric or alpha-numeric) which allows
easy accessioning/identification
➢ Request form should have a provisional diagnosis and brief clinical details
Specimen Accessioning/Identification
➢ Performed by the pathologist
➢ Describing the sample macroscopically
➢ Weight and dimensions of the sample are determined
Gross Examination and Sampling
Tissue Processing
➢ Fixation ➢ Dehydration ➢ Clearing ➢ Infiltration ➢ Embedding ➢ Sectioning (+ Floating, Fishing-out, Drying) ➢ Staining ➢ Mounting ➢ Labelling
✓ Used to locate the presence and position of mineral elements in the tissue
✓ Two duplicate sections of alcohol-fixed tissues
MICROINCINERATION
✓ Injection of radioactive isotopes into organs
Fix→Section→Mount + Photographic Emulsion (Ag Halide)→Stain
✓ Determines the relationship and location of the isotopes and cells to be studied
✓ Provides qualitative and quantitative information
AUTORADIOGRAPHY
process that makes use of aromatic oils
CLEARING
reagent used to preserve tissues
FIXATIVE
dye used in fresh tissue preparation &
examination
SUPRAVITAL
reagent for dehydration
ALCOHOL
performed to provide optical differentiation
STAINING
process of removing water from the tissue sample
DEHYDRATION
first step in tissue processing
FIXATION
cutting embedded tissues into very thin slices
SECTIONING
process of replacing aromatic oil with paraffin
INFILTRATION
also known as blocking or casting
EMBEDDING
